Method for monitoring downlink control information by user equipment in wireless communication system, and device therefor

ABSTRACT

Provided are a method for monitoring downlink control information by user equipment in a wireless communication system and user equipment using the method. The method comprises: receiving “control channel candidate number information” indicating the number of control channel candidates for each aggregation level (AL) of a search space (SS) per cell; and in order to detect DCI, monitoring some initial control channel candidates among existing control channel candidates (legacy candidates), wherein the number of the initial control channel candidates is determined based on the control channel candidate number information.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to wireless communication and, moreparticularly, to a method for monitoring downlink control information bya user equipment (UE) in a wireless communication system and a deviceusing the same.

Related Art

International Telecommunication Union Radio (ITU-R) communication sectoris proceeding with standardization of an International mobiletelecommunication (IMT)-Advanced, a next-generation mobile communicationsystem following the 3^(rd)-generation. The IMT-Advanced aims atsupporting Internet protocol (IP)-based multimedia services at a datarate of 1 Gbps in a stationary and low-speed movement state and at adata rate of 100 Mbps in a high speed movement state.

3^(rd)-generation partnership project (3GPP), a system standard thatmeets the requirements of the IMT-Advanced, provides long term evolution(LTE)-Advanced by improving the LTE which is based on an orthogonalfrequency division multiple access (OFDMA)/single carrier-frequencydivision multiple access (SC-FDMA) transmission scheme. The LTE-advancedis one of potential candidates for the IMT-Advanced.

In the existing LTE-A, a maximum of five carriers (cells) are aggregatedto provide carrier aggregation (CA), but, in a future wirelesscommunication system, enhanced CA (eCA) of aggregating a maximum of 32carriers (cells) is considered.

The increase in the number of aggregated carriers (cells) may causevarious problems. For example, it may be difficult or impossible toeffectively monitor downlink control information by an existing searchspace (SS) configuring method for searching for a control channel andthe number of times of blind decoding (BS) of each aggregation level(AL).

Also, according to the existing scheme, only a maximum of eight carriersmay be indicated unless a size of an existing 3-bit carrier indicationfield (CIF) included in downlink control information is changed forbackward compatibility with a legacy terminal. Thus, it is indefinitehow 32 carriers (cells) are to be indicated.

In addition, a maximum number of times of blind decoding that can besupported by each UE to detect downlink control information may differdepending on capabilities of UEs. Also, an amount of control informationto be transmitted to each UE may differ depending on a channel state, adata amount currently required by each UE, and the like. These variablesmay further be increased as the number of carriers to be aggregated isincreased.

SUMMARY OF THE INVENTION

The present invention provides a method for monitoring downlink controlinformation by a user equipment (UE) in a wireless communication systemand a device therefor.

In one aspect, provided is a method for monitoring downlink controlinformation (DCI) by a user equipment (UE) in a wireless communicationsystem. The method includes receiving control channel candidate numberinformation indicating a number of control channel candidates for eachaggregation level (AL) of a search space (SS) per cell and monitoringsome initial control channel candidates among legacy control channelcandidates to detect DCI. The number of the some initial control channelcandidates is determined on the basis of the control channel candidatenumber information.

The SS may be a UE-specific SS.

The control channel candidates may be candidates of a physical downlinkcontrol channel (PDCCH) or an enhanced physical downlink control channel(EPDCCH).

The control channel candidate number information may be provided as aratio of the number of the some initial control channel candidates tothe number of the legacy control channel candidates.

The control channel candidate number information may be providedregarding the number of legacy control channel candidates per AL of anSS per cell.

The control channel candidate number information may consist of 2 bits.

When the 2 bits is ‘00’, ‘01’, ‘10’, or ‘11’, ratios thereof may be 0,0.33, 0.66, and 1, respectively.

The control channel candidate number information may be received througha higher layer signal.

The higher layer signal may be a radio resource control (RRC) message.

The UE may support aggregation of more than 5 cells.

When the UE fails to receive the control channel candidate numberinformation, the UE may monitor legacy control channel candidatesregarding each AL of the SS to detect DCI.

In another aspect, provided is a user equipment (UE). The UE includes aradio frequency (RF) unit transmitting and receiving a radio signal anda processor connected to the RF unit. The processor receives controlchannel candidate number information indicating a number of controlchannel candidates for each aggregation level (AL) of a search space(SS) per cell and monitors some initial control channel candidates amonglegacy control channel candidates to detect DCI. The number of the someinitial control channel candidates is determined on the basis of thecontrol channel candidate number information.

In a wireless communication system supporting aggregation of more thanfive carriers (cells), the number of times of blind decoding peraggregation level (AL) of a search space (SS) may be reduced. Thus,unnecessary power consumption of a UE may be prevented and delay incontrol channel search may also be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the structure of a radio frame in 3GPP LTE/LTE-A.

FIG. 2 shows an example of a resource grid for one slot.

FIG. 3 shows the structure of an uplink subframe.

FIG. 4 shows the structure of a downlink subframe.

FIG. 5 illustrates an EPDCCH.

FIG. 6 is a view illustrating monitoring of a control channel and asearch space (SS).

FIG. 7 is a comparison example of an existing single carrier system anda CA system.

FIG. 8 illustrates non-cross-carrier scheduling and cross-carrierscheduling.

FIG. 9 illustrates an example of determining a size of schedulinginformation in a search space (SS) according to example #3-3.

FIG. 10 illustrates a method for reporting UE capability information ofa UE according to an embodiment of the present disclosure.

FIG. 11 illustrates an operation method of a UE according to theaforementioned rule #17-A or example #17-A-1.

FIG. 12 illustrates mapping between ServingCellID (or SCellID) and aCIF.

FIG. 13 illustrates an SICC-DCI and a MUCC-DCI.

FIG. 14 illustrates an operation method of a UE when the proposed method#14, proposed method #15, proposed method #16, proposed method #20,proposed method #21, proposed method #23, and proposed method #24described above are applied.

FIG. 15 illustrates an example in which a UE blind-decodes only some(E)PDCCH candidates on the basis of signaled information, among theexisting (USS) (E)PDCCH candidates related to a specific cell.

FIG. 16 illustrates an example of applying the aforementioned proposedmethod #28.

FIG. 17 is a block diagram illustrating a BS and a UE.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following technology can be used in a variety of multiple accessschemes, such as Code Division Multiple Access (CDMA), FrequencyDivision Multiple Access (FDMA), Time Division Multiple Access (TDMA),Orthogonal Frequency Division Multiple Access (OFDMA), and SingleCarrier-Frequency Division Multiple Access (SC-FDMA). CDMA can beimplemented using radio technology, such as Universal Terrestrial RadioAccess (UTRA) or CDMA2000. TDMA can be implemented by radio technology,such as Global System for Mobile communications (GSM)/General PacketRadio Service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMAcan be implemented by radio technology, such as IEEE 802.11 (Wi-Fi),IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). IEEE 802.16mis the evolution of IEEE 802.16e, and it provides backward compatibilitywith a system based on IEEE 802.16e. UTRA is part of a Universal MobileTelecommunications System (UMTS). 3^(rd) Generation Partnership Project(3GPP) Long Term Evolution (LTE) is part of an Evolved UMTS (E-UMTS)using Evolved-UMTS Terrestrial Radio Access (E-UTRA). 3GPP LTE adoptsOFDMA in downlink and adopts SC-FDMA in uplink. LTE-Advanced (A) is theevolution of 3GPP LTE. In order to clarify a description, a situation inwhich the present invention is applied to an LTE-A system is assumed,but the technical spirit of the present invention is not limitedthereto.

FIG. 1 shows the structure of a radio frame in 3GPP LTE/LTE-A.

Referring to FIG. 1, the radio frame includes 10 subframes, and each ofthe subframes includes 2 slots. The slots within the radio frame aregiven slot numbers from #0 to #19. The time that is taken for onesubframe to be transmitted is called a Transmission Time Interval (TTI).The TTI can be called a scheduling unit for data transmission. Forexample, the length of one radio frame can be 10 ms, the length of onesubframe can be 1 ms, and the length of one slot can be 0.5 ms. Thestructure of the radio frame is only an example. Accordingly, the numberof subframes included in the radio frame or the number of slots includedin the subframe can be changed in various ways.

FIG. 2 shows an example of a resource grid for one slot.

The slot includes a downlink slot and an uplink slot. The downlink slotincludes a plurality of Orthogonal Frequency Division Multiplexing(OFDM) symbols in a time domain. The OFDM symbol indicates a specifictime interval, and the OFDM symbol may also be called an SC-FDMA symboldepending on a transmission method. The downlink slot includes an N_(RB)number of Resource Blocks (RBs) in a frequency domain. The RB is aresource allocation unit, and the RB includes one slot in the timedomain and a plurality of contiguous subcarriers in the frequencydomain.

The number of RBs N_(RB) included in the downlink slot depends on adownlink transmission bandwidth configured in a cell. For example, in anLTE system, the number N_(RB) can be any one of 6 to 110. An uplink slotcan have the same structure as the downlink slot.

Each element on the resource grid is called a Resource Element (RE). AnRE on the resource grid can be identified by an index pair (k,l) withina slot. Here, k(k=0, . . . , N_(RB)×12-1) is a subcarrier index withinthe frequency domain, and l(l=0, . . . , 6) is an OFDM symbol indexwithin the time domain.

One RB is illustrated as including 7×12 REs, including 7 OFDM symbols inthe time domain and 12 subcarriers in the frequency domain, but thenumber of OFDM symbols and the number of subcarriers within one RB arenot limited thereto. The number of OFDM symbols and the number ofsubcarriers can be changed in various ways depending on the length of aCP, frequency spacing, etc. For example, in the case of a normal CyclicPrefix (CP), the number of OFDM symbols is 7 and in the case of anextended CP, the number of OFDM symbols is 6. In one OFDM symbol, one of128, 256, 512, 1024, 1536, and 2048 can be selected and used as thenumber of subcarriers.

FIG. 3 shows the structure of an uplink subframe.

The uplink subframe can be divided into a control region and a dataregion in a frequency domain. Physical uplink control channels (PUCCHs)on which uplink control information is transmitted are allocated to thecontrol region. Physical uplink shared channels (PUSCHs) through whichdata is transmitted are allocated to the data region. A terminal (userequipment: UE) may send or may not send a PUCCH and a PUSCH at the sametime depending on a configuration.

A PUCCH for one terminal is allocated as an RB pair in a subframe. RBsbelonging to the RB pair occupy different subcarriers in a first slotand a second slot. A frequency occupied by RBs that belong to an RB pairallocated to a PUCCH is changed on the basis of a slot boundary. This iscalled that the RB pair allocated to the PUCCH has been frequency-hoppedin the slot boundary. A terminal can obtain a frequency diversity gainby sending uplink control information through different subcarriers overtime.

Uplink control information transmitted on a PUCCH includes ACK/NACK,Channel State Information (CSI) indicative of a downlink channel state,a Scheduling Request (SR), that is, an uplink radio resource allocationrequest, etc. The CSI includes a Precoding Matrix Index (PMI) indicativeof a precoding matrix, a Rank Indicator (RI) indicative of a rank valuethat is preferred by UE, a Channel Quality Indicator (CQI) indicative ofa channel state, etc.

A PUSCH is mapped to an uplink shared channel (UL-SCH), that is, atransport channel. Uplink data transmitted on the PUSCH can be atransmission block, that is, a data block for an UL-SCH that istransmitted during a TTI. The transmission block can be userinformation. Alternatively, the uplink data can be multiplexed data. Themultiplexed data can be obtained by multiplexing the transmission blockfor the UL-SCH and control information. For example, control informationmultiplexed with data can include a CQI, a PMI, ACK/NACK, an RI, etc.Alternatively, the uplink data may include only control information.

FIG. 4 illustrates a structure of a downlink (DL) subframe.

A DL subframe includes two slots in a time domain and each slot includesseven OFDM symbols in a normal CP (or six OFDM symbols in an extendedCP). A maximum of first three OFDM symbols of a first slot of thesubframe (a maximum of 4 OFDM symbols regarding a 1.4 MHz bandwidth) area control region to which control channels are allocated, and the otherOFDM symbols are a data region to which a physical downlink sharedchannel (PDSCH) is allocated. The PDSCH refers to a change in which abase station (BS) or a node transmits data to a user equipment (UE).

The control channel transmitted in the control region includes aphysical control format indicator channel (PCFICH), a physicalhybrid-ARQ indicator channel (PHICH), and a physical downlink controlchannel (PDCCH).

The PCFICH transmitted in the first OFDM symbol of the subframe carriesa control format indicator (CFI), information regarding the number ofOFDM symbols (i.e., a size of the control region) used for transmissionof control channels within the subframe. After the UE first receives aCFI on the PCFICH, the UE monitors a PDCCH. The PCFICH is transmittedthrough a fixed PCFICH resource of the subframe.

The PHICH carries a ACK(acknowledgement)/NACK(not-acknowledgement)signal for an uplink hybrid automatic repeat request (HARQ). TheACK/NACK signal regarding uplink data transmitted from the UE istransmitted on the PHICH.

The PDCCH is a control channel transmitting downlink control information(DCI). The DCI may include resource allocation of a PDSCH (which mayalso be referred to as “downlink (DL) grant”, resource allocation of aphysical uplink shared channel (PUSCH) (which may also be referred to as“uplink (UL) grant”), an aggregation of a transmission power controlcommand regarding individual UEs of a certain UE group and/or activationof a VoIP (Voice over Internet Protocol).

FIG. 5 illustrates an EPDCCH.

Referring to FIG. 5, an EPDCCH may be positioned to follow an existingcontrol region in a time domain. For example, when the existing controlregion is transmitted in first three OFDM symbols of a subframe, theEPDCCH may be positioned in OFDM symbols positioned to follow the threeOFDM symbols. In a frequency domain, the existing control region and thePEDCCH may be configured to correspond to each other or to be different.For example, the PDCCH is transmitted in the entire system band, whereasthe PEDCCH may be transmitted only in the same frequency band as that ofthe PDSCH transmitted for a specific UE. In FIG. 5, an example in whichthe PEDCCH is transmitted only in some frequency band of the existingcontrol region is illustrated. In the EPDCCH, control information for anadvanced UE may be transmitted. In the EPDCCH, a reference signal fordemodulation of the PDSCH may be transmitted.

FIG. 6 is a view illustrating monitoring of a control channel and asearch space (SS).

A control region of a subframe includes a plurality of control channelelements (CCEs). A CCE is a logical allocation unit used for providing acoding rate based on a state of a wireless channel to a PDCCH andcorresponds to a plurality of resource element groups (REGs). An REGincludes a plurality of resource elements. A format of a PDCCH and thenumber of available bits of the PDCCH are determined according to acorrelation between the number of CCEs and a coding rate provided by theCCEEs. One REG includes four Res, and one CCE includes nine REGs. Inorder to configure one PDCCH, {1, 2, 4, 8} number of CCEs may be used,and each element of {1, 2, 4, 8} is called a CCE aggregation level (AL).

In 3GG LTE/LTE-A, blind decoding (BD) is used to detect a PDCCH. A UEdoes not know, in advance, in which position of a control region a PDCCHof the UE is transmitted. Thus, the UE checks a cyclic redundancy check(CRC) error in a PDCCH received in each of resources in which the PDCCHmay be present (which is called a PDCCH candidate) to determine whethera corresponding PDCCH is a control channel of the UE. This is calledblind decoding.

That is, a plurality of PDCCHs may be transmitted in a control region ofeach subframe. The UE monitors the plurality of PDCCHs in each subframe.Here, monitoring refers to UE attempting blind decoding of a PDCCH.

In the 3GPP LTE, in order to reduce a burden of blind decoding, a searchspace (SS) is used. The SS may be a monitoring set of a CCE for a PDCCHor may be a set of PDCCH candidates. The UE monitors a PDCCH in acorresponding SS.

The SS is divided into a common SS (CSS) and a UE-specific search space(USS). The CSS, a space for searching for a PDCCH having common controlinformation, includes 16 control channel elements (CCEs) from CCEindices 0 to 15 and supports a PDCCH having a CCE aggregation level (AL)of {4, 8}. However, even in the CSS, a PDCCH (DCI formats 0, 1A)carrying UE-specific information may be transmitted. The UE-specific SSsupports a PDCCH having a CCE AL of {1, 2, 4, 8}.

A starting point of a SS is defined to be different in the CSS and inthe UE-specific SS. A starting point of the CSS is fixated, regardlessof subframe, while a starting point of the UE-specific SS may differ ineach subframe according to a UE identifier (e.g., C-RNTI), a CCE ALand/or a slot number of a radio frame. When a starting point of theUE-specific SS is within the CSS, the UE-specific SS and the CSS mayoverlap. In FIG. 6, a PDCCH is illustrated and described, but an SS mayalso be configured for an EPDCCH, like the PDCCH. An SS of the EPDCCHincludes an ECCE.

<Carrier Aggregation (CA)>

Hereinafter, CA will be described.

FIG. 7 is a comparison example of an existing single carrier system anda CA system.

Referring to FIG. 7, in a single carrier system, only a single carrieris supported for UE in uplink and downlink. The bandwidth of a carriermay be various, but the number of carriers assigned to UE is one. Incontrast, in a Carrier Aggregation (CA) system, a plurality of CCs DLCCs A to C and UL CCs A to C may be assigned to UE. A Component Carrier(CC) means a carrier used in a CA system, and it may be abbreviated as acarrier. For example, in order to allocate a bandwidth of 60 MHz to UE,3 CCs each having 20 MHz may be assigned to the UE.

A CA system may be divided into a contiguous CA system in whichaggregated carriers are contiguous to each other and a non-contiguous CAsystem in which aggregated carriers are separated from each other. Whenit is simply called a CA system hereinafter, it should be understoodthat the CA system includes a case where CCs are contiguous and a casewhere CCS are not contiguous.

A CC, that is, a target when one or more CCs are aggregated, may usebandwidths used in an existing system for backward compatibility withthe existing system. For example, a 3GPP LTE system supports bandwidthsof 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz. A 3GPP LTE-Asystem may configure a broadband of 20 MHz or higher using only thebandwidths of the 3GPP LTE system. Alternatively, a 3GPP LTE-A systemmay configure a broadband by defining new bandwidths without using thebandwidths of an existing system.

The system frequency band of a wireless communication system is dividedinto a plurality of carrier frequencies. In this case, the carrierfrequency means the center frequency of a cell. Hereinafter, a cell maymean downlink frequency resources and uplink frequency resources.Alternatively, a cell may mean a combination of downlink frequencyresources and optional uplink frequency resources. Furthermore, ingeneral, if a CA is not taken into consideration, a single cell mayalways include uplink and downlink frequency resources that form a pair.

In order for packet data to be transmitted and received through aspecific cell, UE first has to complete a configuration for the specificcell. In this case, the configuration means a state in which thereception of system information necessary to transmit and receive datato and from the specific cell has been completed. For example, theconfiguration may include an overall process of receiving commonphysical layer parameters necessary for the transmission/reception ofdata, Medium Access Control (MAC) layer parameters, or parametersnecessary for a specific operation in the RRC layer. Aconfiguration-completed cell is in a state in which the cell mayimmediately transmit and receive packet data only it has only to receiveinformation about which the packet data may be transmitted.

A cell in the configuration-completed state may be in the activation ordeactivation state. In this case, the activation refers to a state inwhich data is being transmitted or received or a state in which data isready to be transmitted or received. UE may monitor and receive thecontrol channel (PDCCH) and data channel (PDSCH) of an activated cell inorder to check resources (they may be the frequency, the time, etc.)assigned thereto.

Deactivation refers to a state in which traffic data cannot betransmitted or received, but measurement or the transmission/receptionof minimum information are possible. UE may receive necessary SystemInformation (SI) in order to receive packets from a deactivated cell. Incontrast, the UE does not monitor or receive the control channel (PDCCH)and data channel (PDSCH) of a deactivated cell in order to checkresources (they may be a frequency, time, etc.) assigned thereto.

Cells may be classified into a primary cell, a secondary cell, and aserving cell.

The primary cell means a cell that operates in a primary frequency, acell in which UE performs an initial connection establishment procedureor a connection re-establishment procedure with a BS, or a cell that isindicated as a primary cell in a handover process.

The secondary cell means a cell that operates in a secondary frequency.The secondary cell is configured once RRC establishment is set up andused to provide additional radio resources.

The serving cell is formed of a primary cell in the case of UE in whicha Carrier Aggregation (CA) has not been configured or to which a CAcannot be provided. If a CA has been configured for UE, the term‘serving cell’ indicates a cell configured for UE and may be plural inthis case. One serving cell may include a single DL CC or a pair of {DLCC, UL CC}. A plurality of serving cells may include a primary cell andone of all secondary cells or a set of a plurality of secondary cells.

A Primary Component Carrier (PCC) means a Component Carrier (CC)corresponding to a primary cell. A PCC is a CC through which UE formsconnection or RRC connection with a BS at the early stage from amongsome CCs. A PCC is a special CC that is responsible for connection orRRC connection for signaling regarding a plurality of CCs and thatmanages UE context, that is, connection information related to UE.Furthermore, a PCC is always in the activation state when it is in RRCconnected mode after forming connection or RRC connection with UE. A DLCC corresponding to a primary cell is called a DL Primary ComponentCarrier (DL PCC), and an UL CC corresponding to a primary cell is calledan UL Primary Component Carrier (UL PCC).

A Secondary Component Carrier (SCC) means a CC corresponding to asecondary cell. That is, an SCC is a CC assigned to UE in addition to aPCC and is a carrier extended for additional resource assignment, etc.by UE in addition to a PCC. An SCC may be divided into the activation ordeactivation state. A DL CC corresponding to a secondary cell is calleda DL Secondary Component Carrier (DL SCC). An UL CC corresponding to asecondary cell is called an UL Secondary Component Carrier (UL SCC).

A primary cell and a secondary cell have the following characteristics.

First, a primary cell is used to transmit a PUCCH. Second, a primarycell is always activated, whereas a secondary cell is a carrier that isactivated or deactivated according to specific conditions. Third, when aprimary cell experiences a Radio Link Failure (hereinafter referred toas an RLF), RRC re-establishment is triggered. Fourth, a primary cellmay be changed by a change of a security key or by a handover procedurethat is accompanied by a random access channel (RACH) procedure. Fifth,Non-Access Stratum (NAS) information is received through a primary cell.Sixth, in the case of an FDD system, a primary cell is always formed ofa pair of a DL PCC and an UL PCC. Seventh, a different CC may beconfigured as a primary cell in each UE. Eighth, a primary cell may bereplaced through only a handover process or a cell selection/cellreselection process. In adding a new secondary cell, RRC signaling maybe used to transmit system information about a dedicated secondary cell.

In relation to a CC that forms a serving cell, a DL CC may form a singleserving cell, or a DL CC and an UL CC may form a single serving cellthrough connection establishment. However, a serving cell is not formedof only a single UL CC.

The activation/deactivation of a CC has the same concept as theactivation/deactivation of a serving cell. For example, assuming that aserving cell1 is formed of a DL CC1, the activation of the serving cell1means the activation of the DL CC1. Assuming that a serving cell2 isconfigured through connection establishment of a DL CC2 and an UL CC2,the activation of the serving cell2 means the activation of the DL CC2and the UL CC2. In this sense, each CC may correspond to a cell.

The number of CCs that are aggregated between downlink and uplink may bedifferently set. A case where the number of aggregated DL CCs is thesame as the number of aggregated UL CCs is called a symmetricaggregation, and a case where the number of aggregated DL CCs isdifferent from the number of aggregated UL CCs is called an asymmetricaggregation. Furthermore, the CCs may have different sizes (i.e.,bandwidths). For example, assuming that 5 CCs are used to form a 70 MHzband, the 70 MHz band may be configured like 5 MHz CC (carrier #0)+20MHz CC (carrier #1)+20 MHz CC (carrier #2)+20 MHz CC (carrier #3)+5 MHzCC (carrier #4).

As described above, unlike a single carrier system, a CA system cansupport a plurality of CCs, that is, a plurality of serving cells.

Such a CA system can support non-cross-carrier scheduling andcross-carrier scheduling.

FIG. 8 illustrates non-cross-carrier scheduling and cross-carrierscheduling.

Non-cross-carrier scheduling may be said to be a method of simplyextending and applying a conventional scheduling method in a single cellto a plurality of cells. If there is a PDSCH scheduled by a PDCCH, thePDCCH/PDSCH is transmitted through the same CC, and the PDCCH mayschedule a PUSCH transmitted through a CC basically linked to a specificCC.

Cross-carrier scheduling is a scheduling method capable of performingthe resource assignment of PDSCHs transmitted through different CCsand/or the resource assignment of PUSCHs transmitted through CCs otherthan CCs basically linked to a specific CC, through a PDCCH transmittedthrough the specific CC. That is, a PDCCH and a PDSCH may be transmittedthrough different DL CCs, and a PUSCH may be transmitted through anotherUL CC other than an UL CC that is linked to a DL CC on which a PDCCHincluding an UL grant has been transmitted. As described above, in asystem supporting cross-carrier scheduling, a carrier indicatorinforming that a PDSCH/PUSCH providing control information aretransmitted through what DL CC/UL CC is necessary for a PDCCH. A fieldincluding such a carrier indicator is hereinafter called a CarrierIndication Field (CIF).

A CA system supporting cross-carrier scheduling may include a CIF in aconventional Downlink Control Information (DCI) format. In a systemsupporting cross-carrier scheduling, for example, in an LTE-A system, 3bits may be extended because a CIF is added to an existing DCI format(i.e., a DCI format used in LTE). In the structure of a PDCCH, anexisting coding method and resource assignment method (i.e., resourcemapping based on a CCE) may be reused.

Hereinafter, the present disclosure will be described.

The present disclosure proposes a method for effectivelyconfiguring/operating a search space (SS) (a discovery region) in caseswhere a large number of cells are configured by carrier aggregation (CA)to support an increasing demand of downlink (DL) and/or uplink (UL)data. Hereinafter, for the purposes of description, a search space (adiscovery region) may be called an “SS”. The SS may be a region in whicha UE discovers/searches/monitors a control channel such as a PDCCH or anEPDCCH.

A plurality of cells configured through CA may be configured only aslicensed spectrum-based cells (which may also be called a “LCELLs”), maybe configured as a combination of an unlicensed spectrum-based cells(which may also be called a “UCELLs”) and the LCELL, or may beconfigured only as UCELLs. The UCELL may be a cell operated in an LTE-Umanner. The UCELL may be limitedly configured only as a secondary cell.Or, a rule may be defined such that the UCELL is cross-carrier-scheduled(CCS) from the LCELL.

Considering that a radio resource pool (RRP) section of the UCELL is aresource configured aperiodically or discontinuously depending on acarrier sensing (CS) result, the corresponding RRP section may bere-defined or re-interpreted in terms of a UE operation and assumption.For example, in the UCELL, the RRP section may be (re)-defined as asection in which the UE is assumed to perform a(time/frequency)synchronization operation regarding the UCELL or inwhich a synchronization signal (e.g., PSS, SSS) therefor is assumed tobe transmitted (from a base station (BS)), a section in which the UE isassumed to perform a CSI measurement operation regarding the UCELL or inwhich a reference signal (e.g., CRS, CSI-RS) therefor is assumed to betransmitted (from the BS), a section in which the UE performs a datatransmission(/reception)-related DCI detection operation in the UCELL,and/or a section in which the UE performs a (temporary or provisional)buffering operation on a signal received in the UCELL.

Hereinafter, for the purposes of description, the proposed scheme willbe described on the basis of the 3GPP LTE/LTE-A. However, the presentdisclosure is not limited thereto and the system to which the presentdisclosure is applied may extend to any other systems in range.

The method for configuring An SS in which DL control information istransmitted will be described in detail again.

A control region includes a plurality of logical CCE strings. The CCEcorresponds to a plurality of resource element groups (REGs). Forexample, the CCE may correspond to 9 REGs. The REG is used to definemapping control channels to REs. For example, one REG may include fourRes. A CCE string is a set of entire CCEs forming a control region in asubframe.

A plurality of PDCCHs may be transmitted in a control region. A PDCCH istransmitted on one or an aggregation of some contiguous control channelelements (CCEs). A format of a PDCCH and the number of available bits ofthe PDCCH are determined according to the number of CCEs forming a CCEaggregation. Hereinafter, the number of CCEs used for PDCCH transmissionis called a CCE AL. Also, the CCE AL is a CCE unit for searching for aPDCCH. A size of the CCE AL is defined by the number of adjacent CCEs.For example, the CCE AL may be defined by CCEs such as any one number of{1, 2, 4, 8}.

Table 1 below illustrates an example of a PDCCH format and the number ofavailable PDCCH bits according to CCE ALs.

TABLE 1 CCE aggregation Number of Number of PDCCH format level REGsPDCCH bits 0 1 9 72 1 2 18 144 2 4 36 288 3 8 72 576

In the CCE AL {1, 2, 4, 8}, an SS S^((L)) _(k) may be defined as a setof candidate PDCCHs. CCEs corresponding to a candidate PDCCH m of the SSS^((L)) _(k) is given as follows.

L{(Y _(k) +m′)mod └N _(CEE,k) /L┘}+i  [Equation 1]

Here, i=0, 1, . . . , L−1, m=0, . . . , M^((L))−1, and N_(CCE,k) is atotal number of CCEs which may be used for transmission of a PDCCH in acontrol region of a subframe k. The control region includes a set ofCCEs numbered from 0 to N_(CCE,k)−1. M^((L)) is the number of candidatePDCCHs in the CCE AL L in the given SS. In a CSS, Y_(k) is set to 0 fortwo ALs, L=4 and L=8. In a UE-specific SS of the CCE AL L, the variableY_(k) is defined as follows.

Y _(k)=(A·Y _(k-1))mod D  [Equation 2]

Here, Y⁻¹=n_(RNTI)≠0, A=39827, D=65537, k=floor(n_(s)/2), and n_(s)denotes a slot number in a radio frame. Floor(x) denotes a largestinteger among numbers smaller than x.

Table 2 below illustrates an aggregation level, the number of CCEs, andthe number of candidate PDCCHs in a common search space (CSS) and aUE-specific SS.

TABLE 2 Search space S_(k) ^((L)) Number of PDCCH Type Aggregation levelL Size [in CCEs] candidates M^((L)) UE-specific 1 6 6 2 12 6 4 8 2 8 162 Common 4 16 4 8 16 2

Meanwhile, when EPDCCH monitoring is not configured and a carrierindicator field (CIF) is not configured, the UE searches for one PDCCHUE-specific SS in each of ALs 1, 2, 4, and 8 in every non-DRX subframeof each of activated serving cells.

When EPDCCH monitoring is not configured and the CIF is configured, theUE searches for one or more UE-specific SSs from each of the ALs 1, 2,4, and 8 regarding one or more activated serving cells configured byhigher layer signaling in every non-DRX subframe.

When EPDCCH monitoring is configured for a serving cell, the servingcell is activated, and a CIF is not configured for the UE, the UEmonitors one PDCCH UE-specific SS in each of the ALs 1, 2, 4, and 8 inevery non-DRX subframe in which the EPDCCH has not been monitored in theserving cell.

When EPDCCH monitoring is configured for the serving cell, the servingcell is activated, and a CIF is configured for the UE, the UE monitorsone or more PDCCH UE-specific SSs in each of the ALs 1, 2, 4, and 8 inevery non-DRX subframe in which the EPDCCH has not been monitored in theserving cell configured by the higher layer signaling.

In a primary cell, the CSS and the PDCCH UE-specific SS may overlap.

A UE, in which a CIF associated with PDCCH monitoring in a serving cellc is configured, monitors a PDCCH in which the CIF is configured andwhich is CRC-scrambled with a C-RNTI from a PDCCH UE-specific SS of theserving cell c.

A UE, in which a CIF associated with PDCCH monitoring in a primary cellis configured, monitors a PDCCH in which the CIF is configured and whichis CRC-scrambled with a SRS C-RNTI from a PDCCH UE-specific SS of theprimary cell.

A UE may monitor a PDCCH without a CIF in the CSS.

In a serving cell in which the PDCCH is monitored, when a CIF is notconfigured for a UE, the UE monitors a PDCCH without a CIF in a PDCCHUE-specific SS. When a CIF is configured for a UE, the UE monitors aPDCCH with a CIF in the PDCCH UE-specific SS.

When a UE is configured to monitor a PDCCH with a CIF corresponding to asecondary cell from another serving cell, the UE does not monitor aPDCCH of the secondary cell (is not expected to monitor it). For aserving cell in which the PDCCH is monitored, the UE may monitor PDCCHcandidates in the serving cell.

Hereinafter, an EPDCCH allocation procedure will be described.

Regarding each serving cell, one or two EPDCCH PRB sets may beconfigured through higher layer signaling for EPDCCH monitoring of a UE.A PRB pair corresponding to the EPDCCH PRB set is indicated by higherlayer signaling. Each EPDCCH PRB set includes ECCEs numbered from 0 toN_(ECCE,p,k−1). Here, N_(ECCE,p,k) is the number of ECCEs in an EPDCCHPRB set p of a subframe k. The EPDCCH PRB set may be configured in alocalized or distributed manner. The UE monitors one or more EPDCCHcandidates, and here, monitoring refers to attempting decoding eachEPDCCH according to DCI formats to be monitored.

The EPDCCH candidates to be monitored may be defined as a EPDCCHUE-specific SS. Regarding each serving cell, subframes in which the UEis to monitor an EPDCCH UE-specific SS may be configured by higher layersignaling.

The UE does not monitor an PEDCCH in a special subframe, and does notmonitor an EPDCCH in a subframe indicated to decode a PMCH by a higherlayer.

In n AL Lε{1, 2, 4, 8, 16, 32}, when an EPDCCH UE-specific SS isES^((L)) _(k), it may be set as a set of EPDCCH candidates, and EPDCCHPRB set p may be expressed by Equation 3 below.

$\begin{matrix}{{L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + b} \right){mod}\; \left\lfloor {N_{{ECCE},p,k}/L} \right\rfloor} \right\}} + i} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

In Equation 3, i=0, . . . , L−1, and when a CIF regarding a serving cellin which the EPDCCH is monitored is configured, b=n_(CI), or when theCIF is not set, b=0. n_(CI) is a value of CIF. M=0, 1, . . . , M^((L))_(p)−1.

When a CIF regarding the serving cell in which the EPDCCH is monitoredis not configured, M^((L)) _(p) is the number of EPDCCH candidatesregarding the AL L in the EPDCCH PRB set p of the serving cell in whichthe EPDCCH is monitored.

Otherwise, M^((L)) _(p) is the number of EPDCCH candidates regarding theAL L in the EPDCCH PRB set p of the serving cell indicated by n_(CI).

When ECCE corresponding to an EPDCCH candidate is mapped to a PRB setoverlapping a frequency at which a PBCH of the same subframe and asynchronization signal (PSS or SSS) is transmitted, the UE may notmonitor the EPDCCH candidate.

Y_(p,k) may be defined by Equation 4 below.

Y _(p,k)=(A _(p) ·Y _(p,k−1)) mod D  [Equation 4]

Y_(p,−1)=n_(RNTI)≠0, A₀=39827, A₁=39829, D=65537, and k=floor(n_(s)/2).

ALs defining an SS and the number of EPDCCH candidates may be given asfollows.

In cases where one EPDCCH PRB set for distributed transmission isconfigured in the UE, ALs and the number of EPDCCH candidates may bedefined as illustrated in the following tables.

TABLE 3 Number of EPDCCH candidates Number of EPDCCH candidates M_(p)^((L)) for Case 1 M_(p) ^((L)) for Case 2 N_(RB) ^(X) ^(p) L = 2 L = 4 L= 8 L = 16 L = 32 L = 1 L = 2 L = 4 L = 8 L = 16 2 4 2 1 0 0 4 2 1 0 0 48 4 2 1 0 8 4 2 1 0 8 6 4 3 2 1 6 4 3 2 1

TABLE 4 Number of EPDCCH candidates M_(p) ^((L)) for Case 3 N_(RB) ^(X)^(p) L = 1 L = 2 L = 4 L = 8 L = 16 2 8 4 2 1 0 4 4 5 4 2 1 8 4 4 4 2 2

In the above tables, Case 1 includes 1) a case where DCI formats2/2A/2B/2C/2D are monitored in a normal subframe and a normal DL CP andthe number of resource blocks of a DL band is 25 or greater, 2) a casewhere DCI formats 2/2A/2B/2C/2D are monitored in a special subframe anda normal DL CP and the number of resource blocks of a DL band is 25 orgreater, 3) a case where DCI formats 1A/1B/1D/1/2/2A/2B/2C/2D/0/4 aremonitored in a normal subframe and a normal DL CP, 4) a case in whichDCI formats 1A/1B/1D/1/2/2A/2B/2C/2D/0/4 are monitored in a specialsubframe and a normal DL CP, and the like.

Case 2 includes 1) a case where DCI formats 1A/1B/1D/1/2A/2/2B/2C/2D/0/4are monitored in a normal subframe and an extended DL CP, 2) a casewhere DCI formats 1A/1B/1D/1/2A/2/2B/2C/2D/0/4 are monitored in aspecial subframe and a normal DL CP, 3) a case where DCI formats1A/1B/1D/1/2A/2/2B/2C/2D/0/4 are monitored in a special subframe and anextended DL CP, and the like.

Other cases are included in Case 3.

N^(Xp) _(RB) is the number of PRB pairs constituting an EPDCCH PRB setp.

In cases where one EPDCCH PRB set for localized transmission isconfigured in the UE, ALs and the number of EPDCCH candidates may bedefined as illustrated in the following tables.

TABLE 5 Number of Number of EPDCCH candidates EPDCCH candidates M_(p)^((L)) for Case 1 M_(p) ^((L)) for Case 2 N_(RB) ^(X) ^(p) L = 2 L = 4 L= 8 L = 16 L = 1 L = 2 L = 4 L = 8 2 4 2 1 0 4 2 1 0 4 8 4 2 1 8 4 2 1 86 6 2 2 6 6 2 2

TABLE 6 Number of EPDCCH candidates M_(p) ^((L)) for Case 3 N_(RB) ^(X)^(p) L = 1 L = 2 L = 4 L = 8 2 8 4 2 1 4 6 6 2 2 8 6 6 2 2

In cases where two EPDCCH PRB sets for distributed transmission areconfigured in the UE, ALs and the number of EPDCCH candidates may bedefined as illustrated in the following tables.

TABLE 7 Number of EPDCCH candidates Number of EPDCCH candidates [M_(p1)^((L)), M_(p2) ^((L))] for Case 1 [M_(p1) ^((L)), M_(p2) ^((L))] forCase 2 N_(RB) ^(Xp) ¹ N_(RB) ^(Xp) ² L = 2 L = 4 L = 8 L = 16 L = 32 L =1 L = 2 L = 4 L = 8 L = 16 2 2 4, 4 2, 2 1, 1 0, 0 0, 0 4, 4 2, 2 1, 10, 0 0, 0 4 4 3, 3 3, 3 1, 1 1, 1 0, 0 3, 3 3, 3 1, 1 1, 1 0, 0 8 8 3, 32, 2 1, 1 1, 1 1, 1 3, 3 2, 2 1, 1 1, 1 1, 1 4 2 5, 3 3, 2 1, 1 1, 0 0,0 5, 3 3, 2 1, 1 1, 0 0, 0 8 2 4, 2 4, 2 1, 1 1, 0 1, 0 4, 2 4, 2 1, 11, 0 1, 0 8 4 3, 3 2, 2 2, 1 1, 1 1, 0 3, 3 2, 2 2, 1 1, 1 1, 0

TABLE 8 Number of EPDCCH candidates [M_(p1) ^((L)), M_(p2) ^((L))] forCase 3 N_(RB) ^(Xp) ¹ N_(RB) ^(Xp) ² L = 1 L = 2 L = 4 L = 8 L = 16 2 22, 2 3, 3 2, 2 1, 1 0, 0 4 4 2, 2 2, 2 2, 2 1, 1 1, 1 8 8 2, 2 2, 2 2, 21, 1 1, 1 4 2 3, 1 3, 2 3, 1 1, 1 1, 0 8 2 3, 1 4, 1 3, 1 1, 1 1, 0 8 42, 2 2, 2 2, 2 1, 1 1, 1

In cases where two EPDCCH PRB sets for localized transmission areconfigured in the UE, ALs and the number of EPDCCH candidates may bedefined as illustrated in the following tables.

TABLE 9 Number of Number of EPDCCH candidates EPDCCH candidates [M_(p1)^((L)), M_(p2) ^((L))] for Case 1 [M_(p1) ^((L)), M_(p2) ^((L))] forCase 2 N_(RB) ^(Xp) ¹ N_(RB) ^(Xp) ² L = 2 L = 4 L = 8 L = 16 L = 1 L =2 L = 4 L = 8 2 2 4, 4 2, 2 1, 1 0, 0 4, 4 2, 2 1, 1 0, 0 4 4 3, 3 3, 31, 1 1, 1 3, 3 3, 3 1, 1 1, 1 8 8 3, 3 3, 3 1, 1 1, 1 3, 3 3, 3 1, 1 1,1 4 2 4, 3 4, 2 1, 1 1, 0 4, 3 4, 2 1, 1 1, 0 8 2 5, 2 4, 2 1, 1 1, 0 5,2 4, 2 1, 1 1, 0 8 4 3, 3 3, 3 1, 1 1, 1 3, 3 3, 3 1, 1 1, 1

TABLE 10 Number of EPDCCH candidates [M_(p1) ^((L)), M_(p2) ^((L))] forCase 3 N_(RB) ^(Xp) ¹ N_(RB) ^(Xp) ² L = 1 L = 2 L = 4 L = 8 2 2 3.3 3.31.1 1.1 4 4 3.3 3.3 1.1 1.1 8 8 3.3 3.3 1.1 1.1 4 2 4.2 4.2 1.1 1.1 8 24.2 4.2 1.1 1.1 8 4 3.3 3.3 1.1 1.1

In cases where one EPDCCH PRB set for distributed transmission and oneEPDCCH PRB set for localized transmission are configured in the UE, ALsand the number of EPDCCH candidates may be defined as illustrated in thefollowing tables.

TABLE 11 Number of EPDCCH candidates Number of EPDCCH candidates [M_(p1)^((L)), M_(p2) ^((L))] for Case 1 [M_(p1) ^((L)), M_(p2) ^((L))] forCase 2 N_(RB) ^(Xp) ¹ N_(RB) ^(Xp) ² L = 2 L = 4 L = 8 L = 16 L = 32 L =1 L = 2 L = 4 L = 8 L = 16 2 2 4, 4 2, 2 1, 1 0, 0 0, 0 4, 4 2, 2 1, 10, 0 0, 0 4 4 4, 2 4, 3 0, 2 0, 1 0, 0 4, 2 4, 3 0, 2 0, 1 0, 0 8 8 4, 14, 2 0, 2 0, 2 0, 1 4, 1 4, 2 0, 2 0, 2 0, 1 2 4 4, 3 2, 4 0, 2 0, 1 0,0 4, 3 2, 4 0, 2 0, 1 0, 0 2 8 4, 1 2, 2 0, 4 0, 2 0, 1 4, 1 2, 2 0, 40, 2 0, 1 4 2 5, 2 4, 2 1, 1 1, 0 0, 0 5, 2 4, 2 1, 1 1, 0 0, 0 4 8 4, 14, 2 0, 2 0, 2 0, 1 4, 1 4, 2 0, 2 0, 2 0, 1 8 2 5, 1 4, 2 2, 1 1, 0 0,0 5, 1 4, 2 2, 1 1, 0 0, 0 8 4 6, 1 4, 2 0, 2 0, 1 0, 0 6, 1 4, 2 0, 20, 1 0, 0 _(p1) is the identity of the localized EPDCCH-PRB-set, _(p2)is the identity of the distributed EPDCCH-PRB-set

TABLE 12 Number of EPDCCH candidates [M_(p1) ^((L)), M_(p2) ^((L))] forCase 3 N_(RB) ^(Xp) ¹ N_(RB) ^(Xp) ² L = 1 L = 2 L = 4 L = 8 L = 16 2 24, 1 4, 2 2, 2 0, 1 0, 0 4 4 4, 1 4, 1 2, 2 0, 1 0, 1 8 8 4, 1 4, 1 2, 20, 1 0, 1 2 4 4, 1 4, 1 2, 2 0, 1 0, 1 2 8 4, 1 4, 1 2, 2 0, 1 0, 1 4 24, 1 4, 1 2, 2 1, 1 0, 0 4 8 4, 1 4, 1 2, 2 0, 1 0, 1 8 2 4, 1 4, 1 4, 10, 1 0, 0 8 4 4, 1 4, 1 2, 2 0, 1 0, 1

When a CIF is not configured in the UE, the UE monitors one EPDCCHUE-specific SS regarding each of the ALs provided in the Table 3 toTable 12 in each of activated serving cells configured to monitor anEPDCCH.

When EPDCCH monitoring is configured and a CIF is configured, the UE maymonitor one or more EPDCCH UE-specific SSs regarding each of the ALsgiven in Table 3 to Table 12 in each of one or more activated servingcells configured by higher layer signaling.

A UE, in which a CIF associated with EPDCCH monitoring in a serving cellc is configured, monitors an EPDCCH in which the CIF is configured andwhich is CRC-scrambled with a C-RNTI from an EPDCCH UE-specific SS ofthe serving cell c.

A UE, in which a CIF associated with EPDCCH monitoring in a primary cellis configured, monitors an EPDCCH in which the CIF is configured andwhich is CRC-scrambled with a SRS C-RNTI from an EPDCCH UE-specific SSof the primary cell.

The UE may monitor a PDCCH without a CIF in the CSS.

In a serving cell in which the EPDCCH is monitored, when a CIF is notconfigured for a UE, the UE monitors an EPDCCH without a CIF from anEPDCCH UE-specific SS. When a CIF is configured for a UE, the UEmonitors an EPDCCH with a CIF in the EPDCCH UE-specific SS.

When the UE is configured to monitor an EPDCCH with a CIF correspondingto a secondary cell from another serving cell, the UE may not monitor anEPDCCH in the secondary cell.

The related art CA presupposes that up to 5 cells are aggregated.However, in a future wireless communication technology, CA ofaggregating cells more than 5 ones, e.g., a maximum of 32 cells, is alsoconsidered. When the number of cells is increased, various matters areto be considered. For example, in the case of using cross-carrierscheduling, how a search space (SS) is to be configured if DL controlinformation (DCI) regarding a maximum of 32 cells is transmitted in ascheduling cell in which scheduling information of other cells istransmitted may be an issue.

The following proposed schemes propose a method effectivelyconfiguring/operating a search space (SS) (or a discovery region) forsearching/discovering a control channel (or control information) when alarge number of cells are configured by CA scheme. By applying some (orall) of the corresponding proposed schemes, SS(s) related to multiplecell(s) may be effectively shared on a specific cell.

Also, in the present disclosure, a proportional increase in the numberof times of blind decoding (BD) as a large number of cell(s) areconfigured may also be alleviated.

In cases where a first cell transmits scheduling information of a secondcell (in cases where scheduling information of the second cell istransmitted through the first cell), the first cell may be referred toas a scheduling cell and the second cell may be referred to as ascheduled cell. The first and second cells may be the same or different.A case in which the first and second cells are different cellscorresponds to the aforementioned cross-carrier scheduling (CCS). SinceRRP is configured for each Ucell appears aperiodically ordiscontinuously according to a carrier sensing (CS) result of eachUcell, a probability in which a large number of Ucell(s) RRP(s) aresimultaneously configured at a specific timing is relatively low. Inother words, a probability in which a large number of UCELL(s) RRP(s)are simultaneously configured at a specific timing and a large amount ofscheduling information related to data transmission is simultaneouslytransmitted in the corresponding Ucell(s) RRP(s) is low. That is, aprobability in which scheduling information regarding Ucells issimultaneously transmitted on an SS of a specific cell such as ascheduling cell scheduling a large number of Ucell(s) is not high. Thus,the corresponding large number of UCELL(s) SS(s) may be shared on aspecific cell (i.e., a scheduling cell of the large number of Ucell(s))through application of some (or all) of the proposed schemes. However,although such a method is applied, a blocking probability (BP) may notbe high. Here, a scheduling cell (related to cross-carrier scheduling)of Ucell(s) may be configured to a Lcell (and/or Pcell and/or(previously configured (or signaled) Ucell), and/or a representativecell of a previously configured (or signaled) cell group (CG) (or aprimary (S)cell of CG). Here, for example, a specific CG may includeonly Ucell(s) including (or not including) a scheduling cell or includea combination of Ucell(s)/Lcell(s) including (or not including) ascheduling cell. Also, for example, in cases where a specific CG doesnot include a scheduling cell, an SS regarding a plurality of previouslyconfigured (or signaled) CG(s)-related cell(s) (i.e., scheduled cell(s))may be configured on one scheduling cell.

Also, for example, in cases where a scheduling cell may be configured toa representative cell of a previously configured (or signaled) CG (orprimary (S)cell) of the CG), an SS regarding the other remaining cell(s)of the corresponding CG may be configured on the correspondingrepresentative cell (or primary (S)cell). Also, for example, a rule maybe defined such that a common search space (CSS) is (exceptionally)defined on the representative cell of the CG described above (or primary(S)cell of the CG). Also, for example, some (or all) of the proposedschemes of the present disclosure may be extendedly applied to an SSconfiguration on a scheduling cell of Lcell(s), as well as a schedulingcell of a Ucell(s).

Hereinafter, for the purposes of description, a scheduling cell in whicha multiple cell(s)-related SS is configured will be termed a “SCH_CELL”.That is, another cell or a cell in which an SS for monitoring a DCIwhich schedules the cell is configured is termed a “SCH_CELL”. Also, forexample, a rule may be defined such that some (or all) of the proposedschemes of the present disclosure are limitedly applied only to a PDCCHUSS (UE-specific SS)/common search space (CSS) (and/or EPDCCH USS/CSS)configuration. Also, for example, a rule may be defined such that some(or all) of the proposed schemes of the present disclosure are limitedlyapplied only to scheduled cell(s) (and/or SCH-CELL) of (the same systembandwidth (which belongs to the same CG or not), a transmission mode(and/or a CP configuration), a special subframe configuration, and/orthe number of RE(s) available for EPDCCH transmission on a PRB pair ofconfiguration of an EPDCCH set). Also, for example, in some (or all) ofthe proposed schemes of the present disclosure a representative CIFvalue (and/or a representative RNTI value) of each CG may be defined bya UE group-specific value or UE-specific value or CG-specific value).Also, for example, a rule may be defined such that some (or all) of theproposed schemes of the present disclosure are limitedly applied only toa CG including Ucell(s) (and/or Lcell(s)), may be limitedly applied onlyto Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s)) of a CG includingUcell(s) (and/or Lcell(s)), or may be limitedly applied only to a CGincluding only Ucell(s) (or Lcell(s)). Here, in another example, a rulemay be defined such that some (or all) of the proposed methods of thepresent disclosure are limitedly applied only to Ucell(s) (or Lcell(s)or Ucell(s)/Lcell(s)) cross-carrier scheduled (CCS-ed) (and/or Ucell(s)(or Lcell(s) or Ucell(s)/Lcell(s)) self-scheduled (SFS-ed) from apreviously configured (or signaled) SCH_CELL.

[Proposed method #1] A representative CIF (carrier indicator field)value (and/or representative RNTI value) of each cell group (CG) may beinformed to the UE through predefined signaling. The representative CIFvalue may be provided to the UE through higher layer signaling orphysical layer signaling.

Also, for example, when the UE receives the representative CIF value(and/or representative RNTI value) of each cell group, the UEconfigures/discovers a specific scheduled cell SS (and/or SCH_CELL SS)on a previously configured (or signaled) SCH_CELL using a representativeCIF value (and/or representative RNTI value) of a CG to which thecorresponding scheduled cell (and/or SCH_CELL) belongs. Here, in aspecific example, the representative CIF value may be substituted to theaforementioned n_(CI) parameter and the representative RNTI value may besubstituted to an n_(RNTI) parameter.

Also, for example, when the [proposed method #1] is applied, scheduledcell(s) (and/or SCH_CELL) constituting a specific CG share a common SSregion on a previously configured (or signaled) SCH_CELL. In anotherexample, when the [proposed method #1] is applied, the UE performs BD onscheduling information (i.e., (UL/DL) DCI format (or (UL/DL) grant))related to (entire) configuration scheduled cell(s) (and/or SCH_CELL) ofthe CG through a single (common) SS region configured on the basis of(previously signaled (or designated)) representative CIF value and/orrepresentative RNTI value. In another example, a rule may be definedsuch that a representative CIF value (and/or representative RNTI value)is information by UE groups through pre-defined signaling. Here, forexample, the corresponding signaling may be defined as higher layersignaling or physical layer signaling. In a specific example, a UE whichbelongs to a specific UE group configures/discovers an SS related to aplurality of scheduled cell(s) (and/or SCH_CELL) configured for the UEon a previously configured (or signaled) SCH_CELL (the representative eCIF value is substituted to the n_(CI) parameter and the representativeRNTI value is substituted to the n_(RNTI) parameter) using thecorresponding specific UE group-related representative CIF value (and/orrepresentative RNTI value).

In another example, a rule may be defined such that the [proposed method#1] is limitedly applied only to a cell group including Ucell(s) (and/orLcell(s) (or such that the [proposed method #1] is limitedly applied toUcell(s) (and/or Lcell(s) on a CG including Ucell(s) (and/or Lcell(s)),such that the [proposed method #1] is limitedly applied only to theUcell(s)/Lcell(s), or such that the [proposed method #1] is limitedlyapplied only to a CG including Ucell(s) (or Lcell(s)). Here, in anotherexample, a rule may be defined such that the [proposed method #1] islimitedly applied only to Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s))CCS-ed (and/or Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s)) SFS-ed) froma previously configured (or signaled) SCH_CELL.

[Proposed method #2] Among the scheduled cell(s) (and/or SCH_CELL)constituting a certain cell group (CG), an SS configuration/region of apreviously signaled (or designated) specific scheduled cell (and/orSCH_CELL) may also be shared (or equally assumed) also to the otherconfiguration scheduled cell(s) (and/or SCH_CELL).

Here, for example, the corresponding signaling may be defined as higherlayer signaling or physical layer signaling. Also, for example,application of such rule may also be interpreted such that when the UEuses (or substitutes) a CIF value of a (previously signaled (ordesignated)) specific scheduled cell (and/or SCH_CELL) (and/or apreviously signaled representative RNTI value of each CG) whenconfiguring/discovering an SS of the other configuration scheduledcell(s) (and/or SCH_CELL) of the corresponding cell group (CG).

For example, when the [proposed method #2] is applied, a scheduledcell(s) (and/or SCH_CELL) configuring a specific CG share a common SSregion on a previously configured (or signaled) SCH_CELL. In anotherexample, when the [proposed method #2] is applied, the UE performs BD onscheduling information (i.e., (UL/DL) DCI format (or (UL/DL) grant))related to the other remaining configuration scheduled cell(s) (and/orSCH_CELL) (or corresponding specific scheduled cell (and/or (entire)configuration scheduled cell(s) of CG including SCH_CELL) (and/orSCHE_CELL)) of a CG of a corresponding specific scheduled cell (and/orSCH_CELL) and (specific scheduled cell (and/or SCH_CELL belongingthereto) through a single (common) SS region configured on the basis ofa CIF value of (previously signaled (or designated)) specific scheduledcell (and/or SCH_CELL) and/or a representative RNTI value (of eachpreviously signaled CG). Also, in another example, a rule may be definedsuch that the [proposed method #2] is limitedly applied only to a cellgroup including Ucell(s) (and/or Lcell(s) (or such that the [proposedmethod #2] is limitedly applied to Ucell(s) (and/or Lcell(s) on a CGincluding Ucell(s) (and/or Lcell(s)), such that the [proposed method #2]is limitedly applied only to the Ucell(s)/Lcell(s), or such that the[proposed method #2] is limitedly applied only to a CG includingUcell(s) (or Lcell(s)). Here, in another example, a rule may be definedsuch that the [proposed method #2] is limitedly applied only to Ucell(s)(or Lcell(s) or Ucell(s)/Lcell(s)) CCS-ed (and/or Ucell(s) (or Lcell(s)or Ucell(s)/Lcell(s)) SFS-ed) from a previously configured (or signaled)SCH_CELL.

[Proposed method #3] The following some or all of rules may be appliedwhen an Ss related to multiple scheduled cell(s) (and/or SCH_CELL) isconfigured (or shared) on a previously configured (or signaled) SCH_CELLthrough application of some or all of the proposed methods (e.g., atleast one of [proposed method #1] and [proposed method #2]).

In another example, a rule may be defined such that the [proposed method#3] is limitedly applied only to a cell group (CG) including Ucell(s)(and/or Lcell(s)). Or, a rule may be defined such that the [proposedmethod #3] is limitedly applied only to Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s)) of a CG including U cell(s) (and/or Lcell(s)). Or, arule may be defined such that the [proposed method #3] is limitedlyapplied only to a CG including only Ucell(s) (or Lcell(s)). Here, inanother example, a rule may be defined such that the [proposed method#3] is limitedly applied only to Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s)) CCS-ed (and/or Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s)) SFS-ed) from a previously configured (or signaled)SCH_CELL.

Example #3-1

In the [proposed method #1], for example, a rule may be defined suchthat a representative CIF value of each CG is used only whenconfiguring/discovering an SS of scheduled cell(s) (and/or SCH_CELL)included in a specific CG (that is, the representative CIF value issubstituted to the n_(CI) parameter) and a CIF value of a (UL/DL) DCIformat (or (UL/DL) grant, the same hereinafter) indicating schedulinginformation of an individual scheduled cell (and/or SCH_CELL) isconfigured to SERVCELLINDEX of each scheduled cell (and/or SCH_CELL).

Also, for example, in the [proposed method #2], a rule may be definedsuch that a CIF value of a specific scheduled cell (and/or SCH_CELL) isused only when configuring/discovering an SS of remaining scheduledcell(s) (and/or SCH_CELL) of a cell group (CG) (to which thecorresponding specific scheduled cell (and/or SCH_CELL) belongs) (e.g.,the representative CIF value is substituted to the n_(CI) parameter) anda CIF value on a (UL/DL) DCI format (or (UL/DL) grant) indicatingscheduling information of an individual scheduled cell (and/or SCH_CELL)is configured to SERVCELLINDEX of each scheduled cell (and/or SCH_CELL).

In another example, in the [proposed #1], a rule may be defined suchthat the representative CIF value of each CG is used as a CIF value onthe (UL/DL) DCI format (or (UL/DL) grant) indicating schedulinginformation of an individual scheduled cell (and/or SCH_CELL), as wellas when configuring/discovering an SS of a configuration scheduledcell(s) (and/or SCH_CELL) of a specific CG (e.g., the representative CIFvalue is substituted to the n_(CI) parameter). Here, for example,according to the proposed method, the (UL/DL) DCI format (or (UL/DL)grant) transmitted on the basis of the representative CIF value may alsobe interpreted as scheduling information commonly applied to scheduledcell(s) (and/or SCH_CELL) forming a cell group interworking with (orlinked to) the corresponding representative CIF value. That is, it maybe interpreted as a form of multi-carrier scheduling.

In another example, in the [proposed method #2], a rule may be definedsuch that the CIF value of a specific scheduled cell (and/or SCH_CELL)is also used as a CIF value on the (UL/DL) DCI format (or (UL/DL) grant)indicating scheduling information of an individual scheduled cell(and/or SCH_CELL), as well as when configuring/discovering an SS ofremaining scheduled cell(s) (and/or SCH_CELL) of a cell group (CG) (towhich the corresponding specific scheduled cell (and/or SCH_CELL)belongs) (e.g., the representative CIF value is substituted to then_(CI) parameter).

In another example, in the [proposed method #1] and/or the [proposedmethod #2], in cases where a representative RNTI value of each cellgroup is not set (for example, in cases where a representative CIF valueis configured or in cases where a CIF value of a previously signaled ordesignated specific scheduled cell (and/or SCH_CELL) is used (orsubstituted), the UE configures/discovers a specific scheduled cell SS(and/or SCH_CELL SS) on a previously configured (or signaled) SCH_CELLusing a C-RNTI, or performs CRC parity bit(s) scrambling related toscheduling information (i.e., (UL/DL) DCI format (or (UL/DL) grant)) ofan individual scheduled cell (and/or SCH_CELL).

Example #3-2

In the [proposed method #1], for example, a rule may be defined suchthat the representative RNTI value of each CG is used only whenconfiguring/discovering an SS of configuration scheduled cell(s) (and/orSCH_CELL) of a specific CG (e.g., the representative RNTI value issubstituted to n_(RNTI) parameter) and a C-RNTI is used in CRC paritybit(s) scrambling related to scheduling information (i.e., (UL/DL) DCIformat (or (UL/DL) grant)) of an individual scheduled cell (and/orSCH_CELL).

Also, for example, in the [proposed method #2], the representative RNTIvalue of a specific scheduled cell (and/or SCH_CELL) is used only inconfiguring/discovering an SS of the other remaining configurationscheduled cell(s) (and/or SCH_CELL) of the CG (to which thecorresponding specific scheduled cell (and/or SCH_CELL) belongs) and aC-RNTI is used in CRC parity bit(s) scrambling related to schedulinginformation (i.e., (UL/DL) DCI format (or (UL/DL) grant)) of anindividual scheduled cell (and/or SCH_CELL).

In another example, in the [proposed method #1], a rule may be definedsuch that the representative RNTI value of each CG is also used in CRCparity bit(s) scrambling related to scheduling information (i.e.,(UL/DL) DCI format (or (UL/DL) grant)) of an individual scheduled cell(and/or SCH_CELL), as well as when configuring/discovering an SS of aconfiguration scheduled cell(s) (and/or SCH_CELL) of a specific CG(e.g., the representative RNTI value is substituted to the n_(RNTI)parameter).

In another example, in the [proposed method #2], the representative RNTIvalue of the specific scheduled cell (and/or SCH_CELL) is also used inCRC parity bit(s) scrambling related to scheduling information (i.e.,(UL/DL) DCI format (or (UL/DL) grant)) of an individual scheduled cell(and/or SCH_CELL), as well as when configuring/discovering an SS of theother remaining configuration scheduled cell(s) (and/or SCH_CELL) of theCG (to which the corresponding specific scheduled cell (and/or SCH_CELL)belongs)

In another example, in the [proposed method #1] and/or the [proposedmethod #2], in cases where the representative CIF value of each CG isnot configured (i.e., in cases where only the representative RNTI valueis configured), the UE configures/discovers a specific scheduled cell SS(and/or SCH_CELL SS) from a previously configured (or signaled) SCH_CELLor configure a CIF value on (UL/DL) DCI format (or (UL/DL) grant)indicating scheduling information of an individual scheduled cell(and/or SCH_CELL).

Example #3-3

As described above, in the SS of the SCH_CELL, scheduling information(UL/DL DCI format (i.e., UL/DL grant at the same meaning) regarding theSCH_CELL itself and scheduling information regarding another cell, i.e.,a scheduled cell, may be transmitted. A rule may be defined such that asize (or length) of (UL/DL) DCI format (or (UL/DL) grant) related tomultiple scheduled cell(s) (and/or SCH_CELL) transmitted in the SS ofthe SCH_CELL is set to be equal to a size (or length) of a (UL/DL) DCIformat (or (UL/DL) grant) of a cell (referred to as a “MAX_BW_CELL”)having a largest system bandwidth among the corresponding scheduledcell(s) (and/or SCH_CELL) or a cell (referred to as a “MIN_BW_CELL”)having a smallest system bandwidth among the corresponding scheduledcell(s) (and/or SCH_CELL).

In a specific example, in the case of a (UL/DL) DCI format (or (UL/DL)grant) related to the scheduled cell (and/or SCH_CELL) having a systembandwidth smaller than that of the MAX_BW_CELL, zero padding is applieduntil a size thereof is equal to a size (or length) of the a (UL/DL) DCIformat (or (UL/DL) grant) related to the MAX_BW_CELL.

Also, in another example, a rule may be defined such that a size (orlength) of a (UL/DL) DCI format (or (UL/DL) grant) related to multiplescheduled cell(s) (and/or SCH_CELL) transmitted in the SS of theSCH_CELL is equal to a size (or length) of a (UL/DL) DCI format (or(UL/DL) grant) of previously signaled (or designated) scheduled cell (orSCH_CELL) among the corresponding scheduled cell(s) (and/or SCH_CELL).

Also, in another example, a rule may be defined such that a size (orlength) of a (UL/DL) DCI format (or (UL/DL) grant) related to multiplescheduled cell(s) (and/or SCH_CELL) transmitted in the SS of theSCH_CELL is adjusted according to a system bandwidth signaled (orconfigured) previously for the corresponding purpose.

Also, in another example, a rule may be defined such that a size (orlength) of a (UL/DL) DCI format (or (UL/DL) grant) related to multiplescheduled cell(s) (and/or SCH_CELL) transmitted in the SS of theSCH_CELL is configured (or fit) to be equal to that of a longest (orshortest) one of sizes (or lengths) of (UL/DL) DCI formats (or (UL/DL)grant) related to the corresponding scheduled cell(s) (and/or SCH_CELL).

FIG. 9 illustrates an example of determining a size of schedulinginformation in a search space (SS) according to example #3-3.

In FIG. 9, it is assumed that three preset or signaled cells (CELL#A,CELL#B, CELL#C) share an SS according to some or all of the proposedmethods ([proposed method #1], [proposed method #2], (example #3-1),(example #3-2), and (example #3-3)).

It is assumed that the shared SS is configured in the CELL#A, and also,it is assumed that CELL#A-related (DL/UL) DCI format size>CELL#B-related(DL/UL) DCI format size>CELL#C-related (DL/UL) DCI format size (that is,CELL#B-related DCI format size and CELL#C-related DCI format size fit toCELL#A-related DCI format size having a largest value.

When a UE finally (actually) receives (individual) DCI format (orscheduling information) regarding each cell (CELL#A, CELL#B, andCELL#C), “DCI FORMAT SIZE FITTING”-applied DCI format (or schedulinginformation) is received as illustrated in FIG. 9. That is, DCE formatsof CELL#B and CELL#C are zero-padded to have the same length as that ofa DCI format of CELL#A. As a result, since lengths of the DCI formats ofCELL#A, B, and C are equal, the UE may perform blind decoding on thepremise that the DCI formats have one length, and thus, the number oftimes of attempting blind decoding may be reduced.

In another example, a size (or length) of a (UL/DL) DCI format (or(UL/DL) grant) related to multiple scheduled cell(s) (and/or SCH_CELL)transmitted in the SS of the SCH_CELL may be determined according to apreviously signaled (or designated) system bandwidth and a transmissionmode TM.

Also, in another example, the process of adjusting the sizes (orlengths) of (UL/DL) DCI formats (or (UL/DL) grant) related to multiplescheduled cell(s) (and/or SCH_CELL) transmitted in the SS of theSCH_CELL to be equal, as described above, may be separately (orindependently) performed on a (previously designated (or signaled) TMcommon DCI format and a (previously designated (or signaled) TMdedicated DCI format. Here, for example, the TM common DCI format may beset to DCI format 0/1A, and the TM dedicated DCI format may be set toDCI format 2C/2D/4(/1B/1D/1/2A/2/2B). That is, in the SS of SCH_CELL,the DCI format 0/1A is adjusted to a DCI format having a first length,and the DCI format 2C/2D/4(/1B/1D/1/2A/2/2B) is adjusted to a DCI formathaving a second length. The first and second lengths may be previouslydetermined or signaled.

Also, in another example, a rule may be defined such that the process ofadjusting the sizes (or lengths) of (UL/DL) DCI formats (or (UL/DL)grant) related to multiple scheduled cell(s) (and/or SCH_CELL)transmitted in the SS of the SCH_CELL to be equal, as described above,is applied only to a specific CG among a CG including only Ucell(s), aCG including only Lcell(s), and both a Ucell and an Lcell.

Also, in another example, a rule may be defined such that (example #3-3)is limitedly applied only to scheduled cell(s) (and/or SCH_CELL) inwhich the same transmission mode TM is set (among multiple scheduledcell(s) (and/or SCH_CELL) sharing the SS of the SCH_CELL). Here, sincesystem bandwidths are different although the transmission mode is thesame, an increase in the number of times of blind decoding may beprevented.

Example #3-4

A rule may be defined such that some (or all) of the followingparameters of previously signaled (or designated) scheduled cells (orSCH_CELL, MAX_BW_CELL, or MIN_BW_CELL) are considered to configure anaggregation level (AL) candidate for (UL/DL) DCI format (or (UL/DL)grant) blind decoding (BD) related to multiple scheduled cell(s) (and/orSCH-CELL) performed in the SS of SCH_CELL and/or determine the number oftimes of BD of each AL. That is, for blind decoding schedulinginformation in the SS of SCH_CELL, an AL, and the number of times ofblind decoding of each AL may be determined. Here, parameters of apredetermined or signaled scheduled cell, a SCH_CELL, a MAX_BW_CELL, ora MIN_BW_CELL may be considered. Here, the parameters may include 1) asystem bandwidth, 2) transmission mode, 3) cyclic prefix configuration,special frame configuration, the number of resource elements (REs) whichmay be used in EPDCCH transmission in a PRB pair forming an EPDCCH(which is called “N_EPDCCH”), and the like.

Here, for example, parameters such as AL candidate configuration, CPconfiguration for finally determining the number of times of blinddecoding for each AL, a special subframe configuration, and or N_EPDCCH(exceptionally) SCH_CELL may be considered.

Also, in another example, it may be defined such that representativeparameters selected according to some (or all) of following rules areconsidered in configuring an AL candidate for (UL/DL) DCI format (or(UL/DL) grant) BD related to multiple scheduled cell(s) (and/orSCH_CELL) performed on the SS of SCH_CELL and/or determining the numberof times of BD for each AL. Here, for example, a rule may be definedsuch that parameters of SCH_CELL are considered as the representativeparameters of the CP configuration for configuring an AL candidateand/or finally determining the number of times of BD in each AL, aspecial subframe configuration, and/or N_EPDCCH.

For example, among system bandwidths of scheduled cell(s) (and/orSCH_CELL), a largest (or smallest) bandwidth may be set as arepresentative system bandwidth value. Also, in another example, amongsystem bandwidths of scheduled cell(s) (and/or SCH_CELL), a largest (orsmallest) number of bandwidths may be set as representative systembandwidths.

For example, among transmission modes TM of scheduled cell(s) (and/orSCH_CELL), a TM having a largest (or smallest) TM-dependent DCI size (orlength) may be set as a representative TM. Also, in another example,among TM(s) of scheduled cell(s) (and/or SCH_CELL) may be set as arepresentative TM.

For example, among CP configuration(s) (or special subframeconfiguration(s) or N_EPDCCH(s)) of scheduled cell(s) (and/or SCH_CELL),a largest (or smallest) number of CP configurations (or special subframeconfigurations or N_EPDCCHs) may be set as representative CPconfigurations.

In another example, a rule may be defined such that RE(s) numberparameters which may be used for EPDCCH transmission on a systembandwidth, a transmission mode, a CP configuration, and/or aconfiguration PRB pair of a specific EPDCCH set previously signaled (orconfigured) for the purpose in determining an AL candidate configurationfor (UL/DL) DCI format (or (UL/DL) grant) BD related to multiplescheduled cell(s) (and/or SCH_CELL) performed in SS(s) of SCH_CELL. Forexample, when (example #3-3) and/or (example #3-4) are applied, the UEperforms BD on (UL/DL) DCI format (or (UL/DL) grant) related to multiplescheduled cell(s) (and/or SCH_CELL) on an SS of previously configured(or signaled) SCH-CELL.

[Proposed method #22] In order to create “single unified DL grant DCIformat” by (“SS-shared or “non-SS shared”) cells, a cell-related “DCIformat 1A/DCI format 0) size” and “TM-dependent DCI format (e.g., DCIformat 2C/2D size)” may be (re)configured to be equal to a shortest (orshortest) among the two. Through this, the number of times of BD may bereduced. That is, a single DCI format having a common length is used inan SS, and a length thereof is determined according to a longest orshortest DCI format among DCI format 0/1A and DCI formats whose lengthis varied depending on a transmission mode.

Here, for example, when such a rule is applied, a “DCI type indicator”field may be additionally (or newly) defined in a “single unified DLgrant DCI format”, and the corresponding DCI type indicator field servesto indicate which of “DCI format 1A (/DCI format 0) (type)” and“TM-dependent DCI format (type)” a (transmitted/received) “singleunified DL grant DCI format” is. Here, in a specific example, when theUE finally (actually) receives the “single unified DL grant DCI format”,if the DCI type indicator field indicates “DCI format 1A(/DCI format 0)(type)”, “DCI format 1A(/DCI format 0)” which is “DCI format sizefitted” to “TM-dependent DCI format” is (actually) received (on theassumption of “TM-dependent DCI format size>DCI format 1A (/DCI format0)”, and here, the other remaining portion excluding a schedulinginformation field corresponding to the DCI format 1A (/DCI format 0)within the “single unified DL grant DCI format” is padded with a bit ofpredefined (or signaled) value (e.g., “0”).

Also, in another example, in order to create “single unified UL grantDCI format” by (“SS shared” or “non-SS shared”) cells, a rule may bedefined such that a cell-related “DCI format 0(/DCI format 1A) size” and“TM-dependent DCI format (e.g., DCI format 4) size” is (re)set (oradjusted) to be the same as a longest (or shortest) among the two.

[Proposed method #4] For example, cell(s) configured to the same cellgroup (CG) may be interpreted such that some or all of the followingparameters are equally configured (or shared). In other words, all (orsome) of the following parameters may be interpreted to be configured inunits of CGs.

Also, in another example, a rule may be defined such that all (or some)of the following parameters are configured such that only the samecell(s) are configured to the same cell group.

In another example, a rule may be defined such that the [proposed method#4] is limitedly applied only to a CG including Ucell(s) (and/orLcell(s)), or a rule may be defined such that the [proposed method #4]is limitedly applied only to Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s))of a CG including Ucell(s) (and/or Lcell(s)). Or, a rule may be definedsuch that the “proposed method #4] is limitedly applied only to a CGincluding only Ucell(s) or Lcell(s).

Also, in another example, a rule may be defined such that the [proposedmethod #4] is limitedly applied only to Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s))CCS-ed (and/or Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s)) SFS-ed) from a previously configured (or signaled)SCH CELL.

Parameters in the [proposed method #4] are as follows.

1) TM and/or system bandwidth and/or CP configuration and/or specialsubframe configuration (and/or N-EPDCCH)

2) Aperiodic CSI (A-CSI) reporting-related serving cell(s) set and/orCSI process(es) set interworking by values (or states) of a CSI requestfield

3) Periodic CSI (P-CSI) reporting configuration

4) ((E)PDCCH) USS (and/or CSS)

[Proposed method #5] For example, control channel information (and/or SStype information) interworking (or to be monitored) by cell groups (orcells) may be provided to the UE through predefined signaling. Here, forexample, the corresponding signaling may be defined as higher layersignaling or physical layer signaling. Also, for example, thecorresponding control channel information may be indicated by one ofPDCCH (USS and/or CSS) and EPDCCH (USS), indicated by one of PDCCH (USSand/or CSS), EPDCCH SET#0 (USS), and EPDCCH set#1 (USS) (in cases wheretwo EPDCCH set(s) are configured), or indicated by one of EPDCCH SET#0(USS) and EPDCCH set#1 (USS) (in cases where two EPDCCH set(s) areconfigured).

In a specific example, in cases where two CG(s) (e.g., CG#0 and CG#1)are configured, it may be configured such that scheduling information(i.e., (UL/DL) DCI format (or (UL/DL) grant)) related to scheduledcell(s) (and/or SCH_CELL#X) forming the CG#0 is received through a PDCCH(USS and/or CSS) on a previously configured (or signaled) SCH_CELL#X,and scheduling information (i.e., (UL/DL) DCI format (or (UL/DL) grant))related to scheduled cell(s) (and/or SCH_CELL#Y) forming the CG#1 isreceived through an EPDCCH (USS) on a previously configured (orsignaled) SCH_CELL#Y.

Here, for example, SCH_CELL#X and SCH_CELL#Y may be configured asdifferent (or the same) cells. Also, in another example, it may beconfigured such that scheduling information (i.e., (UL/DL) DCI format(or (UL/DL) grant)) related to scheduled cell#W (and/or SCH_CELL#A) isreceived through a PDCCH (USS and/or CSS) on a previously configured (orsignaled) SCH_CELL#A and scheduling information (i.e., (UL/DL) DCIformat (or (UL/DL) grant)) related to scheduled cell#Q (and/orSCH_CELL#B) is received through an EPDCCH (USS) on a previouslyconfigured (or signaled) SCH_CELL#B. Here, for example, scheduled cell#Wand scheduled cell#Q may belong to the same CG or different CGs. Also,for example, SCH_CELL#A and SCH_CELL#B may be configured as the samecell (or different cells). Also, in another example, schedulinginformation related to scheduled cell(s) (and/or SCH_CELL#N) forming aCG to which predefined (or signaled) cells belong (i.e., schedulinginformation related to (UL/DL) DCI format (or (UL/DL grant)) (orpredefined (or signaled) scheduled cell (and/or SCH_CELL#N) may beconfigured to be received through a PDCCH (USS and/or CSS) on theSCH_CELL#N (or EPDCCH (USS) or EPDCCH set#0 (USS) or EPDCCH set#1(USS)). Here, for example, the predefined (or signaled) cell may beconfigured as a Pcell.

By applying some rules of the [proposed method #5], for example,excessive concentration of every scheduling information transmissionsrelated to scheduled cell(s) (and/or SCH_CELL) interworking with thecorresponding SCH_CELL on a specific control channel of the SCH_CELL(and/or SS) may be alleviated.

Also, for example, in cases where an SS related to a specific scheduledcell (and/or SCH_CELL) is configured/discovered on a predefined (orsignaled) SCH_CELL by applying the [proposed method #5], some (or all)of the proposed methods (e.g., [proposed method #1], [proposed method#2], [proposed method #3] and [proposed method #4] described above maybe applied together. Also, in another example, a rule may be definedsuch that the [proposed method #5] is limitedly applied only to a CGincluding Ucell(s) (and/or Lcell(s)) (or a rule may be defined such thatthe [proposed method #5] is limitedly applied only to Ucell(s) (orLcell(s) or Ucell(s)/Lcell(s)) of a CG including Ucell(s) (and/orLcell(s)). Here, in another example, a rule may be defined such that the[proposed method #5] is limitedly applied only to Ucell(s) (or Lcell(s)or Ucell(s)/Lcell(s))CCS-ed (and/or Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s)) SFS-ed) from a previously configured (or signaled)SCH_CELL.

[Proposed method #6] For example, a rule may be defined such that an SSrelated to scheduled cell(s) (and/or SCH_CELL#R) configured on theSCH_CELL#R by subframes and a n SS related to a cell group (CG) arepartially (or entirely) different through predefined rule (orsignaling).

Here, for example, corresponding CG and/or scheduled cell(s) may beconfigured as (or limited to) a CG to which the SCH_CELL#R belongsand/or scheduled cell(s) forming the CG to which the SCH_CELL#R belongs,or may be configured as a CG to which SCH_CELL#R does not belong orscheduled cell(s) forming the CG to which the SCH_CELL#R does not belongaccording to a predefined (or signaled) rule. In a specific example, ata subframe #N (SF#N) timing, an SS related to scheduled cell#A (and/orSCH_CELL#R) (belonging to the same CG or different CGs) is configured onthe SCH_CELL#R and, at a subframe #M (SF#M) timing, an SS related toscheduled cell#B (and/or SCH_CELL#R) (belonging to the same CG ordifferent CGs) is configured on the SCH_CELL#R. Also, for example, incases where an SS related to specific scheduled cell (and/or SCH_CELL#R)is configured/discovered on a predefined (or signaled) SCH_CELL#R) byapplying the [proposed method #6], some (or all) of the proposed methods(e.g., proposed method #1), [proposed method #2], [proposed method #3],[proposed method #4], and [proposed method #5] described above may beapplied together.

Also, in another example, a rule may be defined such that the [proposedmethod #6] is limitedly applied only to a CG including Ucell(s) (and/orLcell(s)) (or a rule may be defined such that the [proposed method #6]is limitedly applied only to Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s))of a CG including Ucell(s) (and/or Lcell(s)), or a rule may be definedsuch that the [proposed method #6] is limitedly applied only to a CGincluding only Ucell(s) (or Lcell(s)). Here, in another example, a rulemay be defined such that the [proposed method #6] is limitedly appliedonly to Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s))CCS-ed (and/orUcell(s) (or Lcell(s) or Ucell(s)/Lcell(s)) SFS-ed) from a previouslyconfigured (or signaled) SCH_CELL.

[Proposed method #7] For example, the number of symbols forming acontrol channel or the number of PRB-pairs may be increased throughpredefined rule (or signaling). Here, for example, the control channelmay be interpreted as a PDCCH or an EPDCCH (or EPDCCH set#0, EPDCHset#1).

Before describing the proposed method in detail, an example regardingexisting CFI codeword(s) mapping of each CFI is illustrated in Table 13below.

TABLE 13 CFI code word CFI <b₀, b₁, . . . , b₃₁> 1 <0, 1, 1, 0, 1, 1, 0,1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,1> 2 <1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,0, 1, 1, 0, 1, 1, 0, 1, 1, 0> 3 <1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1> 4 <0, 0, 0, 0,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, (Reserved) 0,0, 0, 0, 0, 0, 0, 0, 0>

A CFI indicates the number of OFDM symbols forming a PDCCH and istransmitted through a PCFICH. The CFI has values of 1, 2, and 3, and incases where the number of resource blocks constituting a system band isgreater than 10, the CFI value sequentially indicates 1, 2, and 3 OFDMsymbols. In cases where the number of resource blocks constituting asystem band is 10 or less, the CFI value sequentially indicates 2, 3,and 4 OFDM symbols.

Also, in another example, a rule may be defined such that the [proposedmethod #7] is limitedly applied only to a CG including Ucell(s) (and/orLcell(s)) (or a rule may be defined such that the [proposed method #7]is limitedly applied only to Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s))on a CG including Ucell(s) (and/or Lcell(s)) or a rule may be definedsuch that the [proposed method #7] is limitedly applied only to a CGincluding only Ucell(s) (or Lcell(s)). Here, in another example, the[proposed method #7] is limitedly applied only to Ucell(s) (or Lcell(s)or Ucell(s)/Lcell(s))CCS-ed (and/or Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s)) SFS-ed) from a previously configured (or signaled)SCH_CELL.

In a specific example, in the case of PDCCH, an additional value may belinked to an advanced UE (A-UE) through predefined signaling by CFIvalues (or CFI states) transmitted through a PCFICH. Here, as an exampleof application of the corresponding rule, existing CFI values 1, 2, 3,(4) may be linked to sequentially indicate 1, 2, 4 (5) OFDM symbols or2, 3, 4 (, 5) OFDM symbols. In such a case, for example, the A-UE mayassume that the number of OFDM symbols corresponding to a CFI value isthe number of symbols constituting a PDCCH.

Table 14 below illustrates an example of mapping between CFI values andCFI codewords.

TABLE 14 CFI for CFI for CFI code word L-UE A-UE <b₀, b₁, . . . , b₃₁> 11 <0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,1, 0, 1, 1, 0, 1, 1, 0, 1> 2 2 <1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0> 3 4 <1, 1, 0,1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,1, 1, 0, 1, 1> (4) (5) <0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,(Reserved) (Reserved) 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0>

Table 14 will be referred to as an example #7-1 hereinafter.

TABLE 15 CFI for CFI for CFI code word L-UE A-UE <b₀, b₁, . . . , b₃₁> 12 <0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,1, 0, 1, 1, 0, 1, 1, 0, 1> 2 3 <1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0> 3 4 <1, 1, 0,1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,1, 1, 0, 1, 1> (4) (5) <0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,(Reserved) (Reserved) 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0>

Table 15 will be referred to as an example #7-2 hereinafter.

An L-UE refers to an existing UE and an A-UE refers to an advanced UE.As can be seen from Table 14 and Table 15, although CFI codewords arethe same, the L-UE and the A-UE may interpret the same CFI codewords tohave different CFI values.

Also, in another example, in the case of PDCCH, it may be configuredsuch that a reserved state (e.g., fourth CIF codeword in the aboveTable) is informed to the A-UE through a PCFICH so that the A-UE caninterpret the corresponding reserved state as a predefined (or signaled)CFI value (e.g., 4). Here, for example, interpretation regarding theother remaining state(s) (e.g., 1, 2, 3) excluding the correspondingreserved state (e.g., 4) is assumed to be the same as the related art.

The following table illustrates an example of applying such a proposedscheme.

TABLE 16 CFI for CFI for CFI code word L-UE A-UE <b₀, b₁, . . . , b₃₁> 11 <0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,1, 0, 1, 1, 0, 1, 1, 0, 1> 2 2 <1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0> 3 3 <1, 1, 0,1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,1, 1, 0, 1, 1> 4 4 <0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,(Reserved) 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0>

Table 16 will be referred to as an example #7-3 hereinafter.

Also, in another example, in the case of PDCCH, an offset value(hereinafter, referred to as “OFFSET”) is informed to the A-UE throughpredefined signaling, and when a CFI value (e.g., “L”) transmittedthrough a PCFICH is interpreted, the corresponding OFFSET may be addedto assume a final CFI value (e.g., “L+OFFSET”).

The following table illustrates an example of applying such a proposedtechnique. Here, an example in which the corresponding OFFSET value isset to 1 (through predefined signaling).

TABLE 17 CFI for CFI for CFI code word L-UE A-UE <b₀, b₁, . . . , b₃₁> 1‘1 + 1’ <0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1> 2 ‘2 + 1’ <1, 0, 1, 1, 0, 1, 1, 0, 1,1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0> 3‘3 + 1’ <1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1> (4) (‘4 + 1’) <0, 0, 0, 0, 0, 0, 0, 0,0, 0, 0, 0, 0, 0, 0, 0, (Reserved) (Reserved) 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0, 0, 0, 0, 0, 0>

Table 17 will be referred to as an example #7-4 hereinafter.

Also, in another example, in cases where some (or all) of the proposedrules described above are applied, it may be defined such that a region(referred to as “LA_REGION”) in which control (/scheduling) informationof the legacy (L-UE) and the advanced UE (A-UE) can be multiplexed and aregion (referred to as an “A-REGION”) in which only control(/scheduling) information of the A-UE can be transmitted areindependently configured.

Here, for example, the LA_REGION may include a (PDCCH) region based onthe existing CFI value, and the A_REGION may include a (PDCCH) regionobtained by subtracting the (PDCCH) region based on the existing CFIvalue from a (PDCCH) region based on an additionally set (or extended)CFI value.

Here, for example, (DCI transmission-related) (E)CCE/(E)REG indexing(and/or mapping) may be independently performed on LA_REGION/A_REGION.In a specific example, in cases where the aforementioned (example #7-2)is configured/applied, if a CFI value indicates “1”, the L-UE interprets(or regards) the corresponding CFI value (equally) as “1”, and the A-UEinterprets (or regards) the corresponding CFI value as (previouslysignaled) “2”. In this context, for example, when the aforementionedproposed method is applied, a region including a first (OFDM) symbol anda region including a second (OFDM) symbol are interpreted (or regarded)as the LA_REGION and A_REGION, respectively, and (DCItransmission-related) (E)CCE/(E)REG indexing (and/or mapping) isindependently performed in the individual regions.

Also, in another example, in cases where the aforementioned example #7-2is configured/applied, if the CFI value indicates “3”, the L-UEinterprets (or regards) the corresponding CFI value (equally) as “3” andthe A-UE interprets (or regards) the corresponding CFI value as(previously signaled) “4”. In this context, for example, when theaforementioned proposed method is applied, a region including first,second and third (OFDM) symbols and a region including a fourth (OFDM)symbol are interpreted (or regarded) as the LA_REGION and the A-REGION,respectively, and (DCI transmission-related) (E)CCE/(E)REG indexing(and/or mapping) is independently performed in the individual regions.

Also, in another example, in cases where a CFI value transmitted to theA-UE indicates a reserved state and the corresponding reserved state isconfigured to be interpreted (or regarded) as “4” through a predefinedrule (or signaling), a region including first, second and third (OFDM)symbols and a region including a fourth (OFDM) symbol are interpreted(or regarded) as the LA_REGION and the A-REGION, respectively, and (DCItransmission-related) (E)CCE/(E)REG indexing (and/or mapping) isindependently performed in the individual regions.

Also, in another example, in cases where a CFI value transmitted to theA-UE indicates a reserved state and the corresponding reserved state isconfigured to be interpreted (or regarded) as “4” through a predefinedrule (or signaling), a region including first, second, third, and fourth(OFDM) symbols is interpreted (or regarded) entirely as the A-REGION (orLA_REGION) and the A-REGION and (DCI transmission-related) (E)CCE/(E)REGindexing (and/or mapping) is performed in the corresponding region.

Also, for example, a rule may be defined such that configuring/mapping a(L-UE/A-UE) PCFICH and/or a PHICH-related resource is performed on theLA_REGION (or configuring/mapping a PHICH-related resource is performedon the basis of a PHICH duration value signaled through a PBCH). Here,in another example, a rule may be defined such that configuring/mappinga PHICH-related resource of the L-UE is performed on the LA_REGION andconfiguring/mapping a PHICH-related resource of the A-UE is performed onthe A_REGION (i.e., configuring/mapping a PCFICH-related resource isperformed on the LA_REGION. Also, in another example, a rule may bedefined such that a PDCCH CSS is (exceptionally) configured on theLA_REGION. Also, in another example, a rule may be defined such that,when some (or all) of the proposed rules described above are applied, aremaining (PDCCH) region obtained by subtracting the existing CFIvalue-based (PDCCH) region from the additionally configured (orextended) CFI value-based (PDCCH) region in the (existing CFI value(i.e., PDSCH starting symbol position)-based) PDSCH region transmittedto the L-UE is punctured in consideration of the fact that the CFIvalues assumed by the L-UE and the A-UE on the corresponding subframeare different.

Also, in another example, a rule may be defined such that A-UE-relatedscheduling information transmission and/or PDSCH transmission areassumed to be performed on a corresponding subframe in cases where some(or all) of the proposed rules described above are applied. Here, forexample, a rule may be defined such that the corresponding subframeinformation is informed to the L-UE through predefined signaling. Whensuch a rule is applied, for example, it may be configured such that,(since there is no L-UE-related control (/scheduling) informationtransmission), configuring/mapping of A-UE-related (DCItransmission-related) (E)CCE/(E)REG indexing (and/or mapping) and/orPCFICH and/or PHICH-related resource is performed on the additionallyconfigured (or extended) CFI value-based (PDCCH) region. Also, inanother example, a rule may be defined such that the some (or all) ofthe proposed rules described above are not applied to a subframe inwhich an SIB and/or PAR and/or PBCH and/or paging is received.

The following tables illustrate an example regarding setting the numberof times of blind decoding (BD) of each AL when one EPDCCH set includes12 PRB-pair(s).

TABLE 18 Number of EPDCCH candidates Number of EPDCCH candidates M_(p)^((L)) for Case 1 M_(p) ^((L)) for Case 2 N_(RB) ^(X) ^(p) L = 2 L = 4 L= 8 L = 16 L = 32 L = 1 L = 2 L = 4 L = 8 L = 16 12 4 4 4 3 1 4 4 4 3 1

In Table 18, regarding one distributed EPDCCH-PRB set, the number ofEPDCCH candidates monitored by a UE for each of Cases 1 and 2 isillustrated.

TABLE 19 Number of EPDCCH candidates M_(p) ^((L)) for Case 3 N_(RB) ^(X)^(p) L = 1 L = 2 L = 4 L = 8 L = 16 12 4 4 4 2 2

In Table 19, regarding one distributed EPDCCH-PRB set, the number ofEPDCCH candidates monitored by a UE for Case 3 is illustrated.

TABLE 20 Number of Number of EPDCCH candidates EPDCCH candidates M_(p)^((L)) for Case 1 M_(p) ^((L)) for Case 2 N_(RB) ^(X) ^(p) L = 2 L = 4 L= 8 L = 16 L = 1 L = 2 L = 4 L = 8 12 6 6 2 2 6 6 2 2

In Table 20, regarding one localized EPDCCH-PRB set, the number ofEPDCCH candidates monitored by a UE for each of Cases 1 and 2 isillustrated.

TABLE 21 Number of EPDCCH candidates M_(p) ^((L)) for Case 3 N_(RB) ^(X)^(p) L = 1 L = 2 L = 4 L = 8 12 6 6 2 2

In Table 21, regarding one localized EPDCCH-PRB set, the number ofEPDCCH candidates monitored by a UE for Case 3 is illustrated.

[Proposed method #8] For example, it may be configured such that, insome (or all) of the proposed methods described above (e.g., [proposedmethods #1 to #7]), scheduled cell(s) (and/or SCH_CELL) having the samerepresentative CIF value (and/or representative RNTI value) share ALcandidate configuration and/or the number of times of BD in each AL, aswell as sharing an SS on a predefined (or signaled) SCH_CELL).

Here, for example, when the corresponding method is applied, scheduledcell(s) (and/or SCH_CELL) having the same representative CIF value(and/or representative RNTI value) may be interpreted as one virtualcell.

For example, in the case of K number of scheduled cell(s) having thesame representative CIF value (and/or representative RNTI value) (e.g.,the same (DL/UL) TM(S)/USS is assumed), when BD is performed onscheduling information ((UL/DL) DCI format (or (UL/DL) grant)) relatedto the corresponding cell(s), ‘{AL, BD}={1, 6}, {2, 6}, {4, 2}, {8, 2}’(or ‘{AL, BD}={1, 3}, {2, 3}, {4, 1}, {8, 1}’ (e.g, it may beinterpreted as a case where the number of times of BD for each AL ishalved (BD (NUMBER) REDUCTION)), or ‘{AL, BD}={1, 6}, {2, 6}, {4, 1 (or0)}, {8, 1 (or 0)}’ (e.g., it may be interpreted as a case where thenumber of times of BD for relatively high ALs is reduced), or ‘{AL,BD}={1, 1 (or 0)}, {2, 1 (or 0)}, {4, 2}, {8, 2}’ (e.g., it may beinterpreted as a case where the number of times of BD for relatively lowALs is reduced), rather than ‘{AL, BD}={1, 6*K}, {2, 6*K}, {4, 2*K}, {8,2*K}’, are applied.

In another example, in the some (or all) of the proposed methodsdescribed above (e.g., [proposed methods #1 to #7]), scheduled cell(s)(and/or SCH_CELL) having the same representative CIF value (and/orrepresentative RNTI value) share only an SS on the predefined (orsignaled) SCH_CELL and AL candidate configuration and/or the number oftimes of BD for each AL are regarded (or configured) to be independent(or not shared). Here, for example, when the corresponding method isapplied, the scheduled cell(s) (and/or SCH_CELL) having the samerepresentative CIF value (and/or representative RNTI value) may shareonly the SS and may be interpreted as independent cell(s).

For example, in the case of K number of scheduled cell(s) having thesame representative CIF value (and/or representative RNTI value) (e.g.,the same (DL/UL) TM(S)/USS is assumed), when BD is performed onscheduling information ((UL/DL) DCI format (or (UL/DL) grant)) relatedto the corresponding cell(s), ‘{AL, BD}={1, 6*K}, {2, 6*K}, {4, 2*K},{8, 2*K}’ (or ‘{AL, BD}={1, 3*K}, {2, 3*K}, 4, {4, 1*K}, {8, 1*K}’(e.g., it may be interpreted as a case where the number of times of BDfor each AL is halved), or ‘{AL, BD}={1, 6*K}, {2, 6*K}, {4, 1*K (or0)}, {8, 1*K (or 0)}’ (e.g., it may be interpreted as a case where thenumber of times of BD for relatively high ALs is reduced), or ‘{AL,BD}={1, 1*K (or 0)}, {2, 1*K (or 0)}, {4, 2*K}, {8, 2*K}’ (e.g., it maybe interpreted as a case where the number of times of BD for relativelylow ALs is reduced) are applied.

In another example, in the case of K number of scheduled cell(s) havingthe same representative CIF value (and/or representative RNTI value)(e.g., the same (DL/UL) TM(S)/USS is assumed), when BD is performed onscheduling information ((UL/DL) DCI format (or (UL/DL) grant)) relatedto the corresponding cell(s), it may be configured to apply ‘{AL,BD}={1, 1*K}, {2, 1*K}, {4, 1*K}, {8, 1*K}’. Here, for example, thecorresponding rule may be useful in cases where a relative small number(e.g., 1) of scheduling information ((UL/DL) DCI format (or (UL/DL)grant)) is transmitted by scheduled cells (from a vantage point of aspecific UE).

Also, for example, such a rule may be limitedly applied to a case wherethe K number of scheduled cell(s) include only Ucell(s) (or Lcell(s) ora combination of Ucell(s) and Lcell(s)). In additional example, a rulemay be defined such that the [proposed method #8] is limitedly appliedonly to cell(s) that belong to the same CG (and/or different CGs).

Also, in another example, a rule may be defined such that the [proposedmethod #8] is limitedly applied only to a CG including Ucell(s) (and/orLcell(s)) (or a rule may be defined such that the [proposed method #8]is limitedly applied only to Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s))of a CG including Ucell(s) (and/or Lcell(s)) or a rule may be definedsuch that the [proposed method #8] is limitedly applied only to a CGincluding only Ucell(s) (or Lcell(s)).

Also, in another example, a rule may be defined such that the [proposedmethod #8] is limitedly applied only to Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s))CCS-ed (and/or Ucell(s) (or Lcell(s) orUcell(s)/Lcell(s)) SFS-ed) from a previously configured (or signaled)SCH CELL.

[Proposed method #9] For example, a rule may be defined such that, insome (or all) of the proposed methods described above (e.g., [proposedmethods #1 to #8]), when an SS related to multiple scheduled cell(s)(and/or SCH_CELL#T) is configured (or shared) in a previously configured(or signaled) SCH_CELL#T, AL candidate configuration for schedulinginformation ((UL/DL) DCI format (or (UL/DL) grant)) BD and/or the numberof times of BD for each AL are configured (or assumed) to be partially(or entirely) different according to cell types.

Here, for example, the corresponding scheduled cell(s) and/or SCH_CELL#Tmay belong to the same CG (or different CGs). In a specific example ofapplication of the proposed method, when a scheduled Ucell#X, ascheduled Ucell#Y, and a scheduling Lcell#T belong to a CG#N and an SSrelated to the scheduled Ucell#X, the scheduled Ucell#Y, and thescheduling Lcell#T is shared (/configured) in the scheduling Lcell#T,‘{AL, BD}={1, 3}, {2, 3}, {4, 1}, {8, 1}’ (e.g., it may be interpretedas a case where the number of times of BD for each AL is halved,compared with Lcell) (or ‘{AL, BD}={1, 6}, {2, 6}, {4, 0}, {8, 0}’(e.g., it may be interpreted as a case where BD is not performed on arelatively high AL(s) or ‘{AL, BD}={1, 0}, {2, 0}, {4, 2}, {8, 2}’(e.g., it may be interpreted as a case where BD is not performed on arelatively low AL(s)) may be configured for the scheduled Ucell#X andthe scheduled Ucell#Y, and ‘{AL, BD}={1, 6}, {2, 6}, {4, 2}, {8, 2}’ maybe configured to the scheduling Lcell#T.

Here, for example, in the corresponding example, a case (i.e., the[proposed method #8] where the scheduled cell(s) (and/or SCH_CELL)having the same representative CIF value (and/or representative RNTIvalue) shares only an SS of the predefined (or signaled) SCH_CELL andthe AL candidate configuration and/or the number of times of BD for eachAL are regarded as being independent (or not shared) is assumed.

Also, in another example, in cases where an SS related to the scheduledUcell#X, the scheduled Ucell#Y, and the scheduling Lcell#T (i.e., CG#N)is shared (/configured) in the scheduling Lcell#T and the AL candidateconfiguration for scheduling information ((UL/DL) DCI format (or (UL/DL)grant)) BD of the corresponding cell(s) and/or the number of times of BDfor each AL is shared (or configured) as ‘{AL, BD}={1, 6}, {2, 6}, {4,2}, {8, 2}’ by applying some (or all) of the proposed methods describedabove (e.g., [proposed methods #1 to #8]), ‘{AL, BD}={1, 2}, {2, 2}, {4,1}, {8, 1}’ (e.g., it may be interpreted as a case where the number oftimes of BD is configured to be smaller than that of Lcell) may be setfor the scheduled Ucell#X and the scheduled Ucell#Y and ‘{AL, BD}={1,4}, {2, 4}, {4, 1}, {8, 1}’ (i.e., the number of times of BD for theentire ALs is maintained as ‘{AL, BD}={1, 6}, {2, 6}, {4, 2}, {8, 2}’)may be set for the scheduling Lcell#T. Here, for example, in thecorresponding example, a case where scheduled cell(s) (and/or SCH_CELL)having the same representative CIF value (and/or representative RNTIvalue) share AL candidate configuration and/or the number of times of BDin each AL, as well as sharing an SS on a predefined (or signaled)SCH_CELL) is assumed (i.e., please refer to the [proposed method #8])

Also, in another example, a rule may be defined such that the [proposedmethod #9] is limitedly applied only to a CG including Ucell(s) (and/orLcell(s)), or a rule may be defined such that the [proposed method #9]is applied only to Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s)) of a CGincluding Ucell(s) (and/or Lcell(s)). Or, a rule may be defined suchthat the [proposed method #9] is limitedly applied only to a CGincluding Ucell(s) (or Lcell(s)). Here, in another example, a rule maybe defined such that the [proposed method #9] is limitedly applied onlyto Ucell(s) (or Lcell(s) or Ucell(s)/Lcell(s))CCS-ed (and/or Ucell(s)(or Lcell(s) or Ucell(s)/Lcell(s)) SFS-ed) from a previously configured(or signaled) SCH CELL.

The existing PDSCH starting position (referred to as “PDSCH_SP”) and anEPDCCH starting position (referred to as “EPDCCH_SP”) may be defined asfollows.

A starting OFDM symbol (positioned in a first slot of a subframe) of aPDSCH of each activated serving cell may be given by an indexI_(DataStart).

Regarding a given activated serving cell, the UE configured by thetransmission mode 1-9 is configured to be allocated a PDSCH by an EPDCCHreceived from the same serving cell or monitor an EPDCCH in a subframe,and in cases where a PDSCH is not allocated by a PDCCH/EPDCCH, ifepdcch-StartSymbol-r11, a higher layer parameter, is configured,l_(DataStart) is given by the epdcch-StartSymbol-r11.

If, however, the PDSCH and the corresponding PDCCH/EPDCCH are receivedfrom different serving cells, l_(DataStart)

is given by a higher layer parameter pdsch-Start-r10 regarding a servingcell from which the PDSCH is received.

In other cases, l_(DataStart) is given by a CFI value. When the numberof resource blocks of a (DL) system band is greater than 10,l_(DataStart) is given as a CIF value, and when the number of resourceblocks of the (DL) system band is equal to or smaller than 10,l_(DataStart)

is given as a CFI value+1.

A starting position of an EPDCCH may be given as follows.

When a UE is configured to receive a PDSCH data transmitted according toa transmission mode 1-9 by a higher layer signal and a higher layersignal epdcch-StartSymbol-r11 has been set, a starting OFDM symbol ofthe EPDCCH is given by an index l_(EPDCCHStart). If not, the startingOFDM symbol of the EPDCCH given by I_(EPDCCHStart) is determined by aCFI value.

For example, in cases where the number of symbols constituting a PDCCHis increased by applying the aforementioned proposed method (e.g.,[proposed method #7], EPDCCH_SP and PDSCH_SP are required to beredefined in consideration of a relatively increased PDCCH region. Inother words, the existing EPDCCH_SP and/or PDSCH_SP may be designated byone of values from 1 (first symbol) to 4 (fourth symbol) through higherlayer signaling. However, if the PDCCH region is increased (ordesignated) to a region from the first symbol to a fifth symbol, amaximum value of the existing EPDCCH_SP and/or PDSCH_SP is 4 (fourthsymbol), causing a problem that the increased PDCCH region and theEPDCCH region and/or PDSCH_SP region overlap. This problem may be solvedby applying the following proposed methods. For example, a rule may bedefined such that the following proposed methods are limitedly appliedonly to a case where EPDCCH_SP-related EPDCCH-STARTSYMBOL-R11 isconfigured, a case of a PDSCH(cell#X) self-scheduled (SFS-ed) from anEPDCCH (cell#X) of the same serving cell#X, a case of a PDSCH (cell#X)cross-carrier scheduled (CCS-ed) from an EPDCCH/PDCCH (cell#Y) of adifferent serving cell #Y, a case of an EPDCCH set scheduling TM 10PDSCH (when the PDSCH-START-R11 is configured and the correspondingPDSCH-START-R11 indicates one of {1, 2, 3, 4}, a case where a predefinedTM (e.g., TM 1 to 9, TM 10) is configured, a case where PDCCH CRCscrambling is performed on the basis of predefined RNTI(s) (e.g.,P-RNTI/RA-RNTI/SI-RNTI/temporary C-RNTI, C-RNTI), a case where a PDSCHis scheduled through a predefined DCI format (e.g., DCI format 1C, DCIformat 1A), a case of an MBSFN SF, a case of a special SF (or TDD SF#1or SF#6), a case where a PDSCH is scheduled from a predefined controlchannel (e.g., PDCCH, EPDCCH), a case where a PDSCH is scheduled on thebasis of an SFS (or CCS), and a case where an (E)PDCCH/PDSCH istransmitted on a predefined cell (e.g., Pcell, Scell, Lcell, Ucell).

[Proposed method #10] A rule may be defined such that, when a finalsymbol position value (referred to as “INC_PDC_LS”) of a PDCCH regionincreased (in an EPDCCH monitoring SF#K as a subframe configured tomonitor an PEDCCH in a specific serving cell#N) is greater than a(serving cell #N-related) EPDCCH_SP value (related to serving cell #N)configured through predefined signaling (or rule) or a threshold value(e.g., 4), the corresponding EPDCCH_SP value is assumed as (or replacedwith) an INC_PDC_LS value.

For example, if the INC_PDC_LS value and the (serving cell#N-related)EPDCCH_SP value are set to 5 and 3, respectively, the EPDCCH_SP valuemay be assumed to be 5.

Also, in another example, a rule may be defined such that, in caseswhere the INC_PDC_LS value is greater than a (serving cell#N-related)PDSCH_SP value configured through predefined signaling (or rule) (or apredefined (or signaled) threshold value (e.g., 4)) (at a point of SF#Kof the specific serving cell #N), the corresponding PDSCH_SP value isassumed as (or replaced with) the INC_PDC_LS value.

Here, for example, the PDSCH_SP value may be configured throughPDSCH-START-R11 or PDSCH-START-R10. In a specific example, if theINC_PDC_LS value and the (serving cell#N-related) PDSCH_SP value arerespectively set to 5 and 3 in the SF#K of the serving cell#N, thePDSCH_SP value may be assumed to be 5.

[Proposed method #11] A rule may be defined such that, when anINC_PDC_LS value at a point of EPDCCH monitoring SF#K of a specificserving cell#N is greater than a (serving cell#N-related) EPDCCH_SPvalue configured through predefined signaling (or rule) (or a predefined(or signaled) threshold value (e.g., 4)) and/or when the INC_PDC_LSvalue (at a SF#K point of the specific serving cell#N) is greater than a(serving cell#N-related) PDSCH_SP value configured through predefinedsignaling (or rule) (or a predefined (or signaled) threshold value(e.g., 4)), a final (serving cell#N-related) EPDCCH_SP value (i.e.,‘(EPDCCH_SP+ST_OFFSET)’) and/or a final PDSCH_SP value (i.e.,‘(PDSCH_SP+ST_OFFSET)’) are calculated by applying a preset (orsignaled) offset value (referred to as “ST_OFFSET”) to the correspondingEPDCCH_SP value and/or the PDSCH_SP value.

For example, in cases where ST_OFFSET is set (or signaled) to 2, if theINC_PDC_LS value and (serving cell#N-related) EPDCCH_SP value arerespectively set to 5 and 3 at the EPDCCH monitoring SF#K of the servingcell#N, a final EPDCCH_SP value is calculated to 5 through computationof (3+2). Also, for example, a rule may be defined such that thecorresponding ST_OFFSET value is (implicitly) assumed to the INC_PDC_LSvalue. Here, for example, when such a rule is applied, an (INC_PDC_LS+1)point may be regarded as a first virtual symbol of the (serving cell#N)SF#K, and a (se serving cell#N-related) EPDCCH_SP value set throughpredefined signaling (or rule) and/or a (serving cell#N-related)PDSCH_SP value set through predefined signaling (or rule) are appliedwith respect to the corresponding first virtual symbol to determine afinal EPDCCH_SP position and/or final PDSCH_SP position. Also, forexample, a rule may be defined such that, in cases where the INC_PDC_LSvalue (at an EPDCCH monitoring SF#K point of the specific servingcell#N) is greater than the (serving cell#N-related) EPDCCH_SP value setthrough predefined signaling (or rule) (or predefined (or signaled)threshold value (e.g., 4)) and/or in cases where the INC_PDC_LS value(at the SF#K of the specific serving cell#N) is greater than a (servingcell#N-related) PDSCH_SP value set through predefined signaling (orrule) (or predefined (or signaled) threshold value (e.g., 4)), a finalEPDCCH_SP position and/or a final PDSCH_SP position are determinedaccording to a predefined (or signaled) specific value.

Hereinafter, UE capability information reported by a UE to a network ina carrier aggregation (CA) situation in which aggregation of a pluralityof cells is supported or in a situation in which a large number ofcell(s) are configured through CA to support an increasing (DL and/orUL) data demand will be described. In the related art CA, aggregation ofa maximum of 5 cells is supported, but in future CA, aggregation ofcells more than 5 ones (e.g., a maximum of 32 cells) may be supported.Here, supporting aggregation of cells more than 5 ones does not meanthat cells more than 5 ones are always aggregated in the case of CA.That is, the UE may support aggregation of cells less than 5 ones. Thepresent disclosure may be applied, regardless of the number ofconfigured cells.

The UE capability information may include at least one of CA (1) BD(blind decoding) capability information, (2) buffering capabilityinformation, and (3) RRM capability information, as well as CAcapability information (e.g., information regarding a maximum number ofcomponent carriers (CC) for the UE to support CA and/or a combination ofCCs). The UE may (independently) report UE capability informationthrough predefined signaling.

The BD capability information may include at least one of the number of(maximum) (USS) PDCCH (or EPDCCH) candidates available for blinddecoding (BD) in one subframe (SF) and the number of CCs capable ofsupporting BD when the (maximum) (USS) BD number of each CC in one SF isassumed to a certain specific value.

Here, for example, the minimum supported number of BD by UE categories(or minimum BD number (/capability) per UE category) may be defined (orsignaled) independently from (or regardless of) CA capability (of UE).Also, in another example, the minimum BD number (/capability) per UEcategory may be interpreted (/defined) as (predefined (or signaled)“unit BD (number)”, and the final (total) BD number supportable by thespecific CA capability and UE of UE category (in one SF (and USS)) maybe determined (/defined).

Also, in another example, the minimum BD number (and/or capability) tobe supported by the UE may be defined (/configured) in proportion to thetotal number of peak data rate (/soft channel bit(s)) (which can besupported by the UE according to UE category of the UE reported (to abase station (BS)) (and/or buffer capability and/or CA capability).

Also, for example, a rule may be defined such that some (or all) ofpieces of information are reported per band (or per band or per bandcombination). Also, for example, a rule may be defined such that the UEreports (or signals) (some or all) of pieces of capability information,or a rule may be defined such that (previously configured (or signaled)combination of capability information is reported (or signaled).

FIG. 10 illustrates a method for reporting UE capability information ofa UE according to an embodiment of the present disclosure.

Referring to FIG. 10, a UE reports UE capability information to a BS(S510). As described above, UE capability information, which informs theBS about capability of the UE, may include BD capability informationindicating (USS) DL control channel decoding capability of eachsubframe. Through the UE capability information, the UE informs the BSabout a (maximum) number for the UE to perform blind decoding on a DLcontrol channel such as a PDCCH/EPDCCH in a USS of a subframe. The BDcapability information may include any one value among a predeterminednumber of candidate values (e.g., 32). That is, the UE reportscapability for decoding (USS) DL control channel by subframes to anetwork. For example, the UE may report a (maximum number of times forblind decoding the PDCCH or the EPDCCH in a UE-specific search space(USS) of a subframe to the network.

The BS determines the number of control channels (EPDCCH and/or PDCCH)candidates regarding each AL of a USS of each cell on the basis of theUE capability information (S520). Information indicating the number ofcontrol channels (EPDCCH or/and PDCH) candidates regarding each AL of aUSS of each cell may be referred to as control channel candidate numberinformation.

The BS transmits the control channel candidate number information to theUE (S530). As described above, the control channel candidate numberinformation may inform about the number of control channels (EPDCCHor/and PDCCH) regarding each AL of a USS of each cell. For example, thecontrol channel candidate number information may be provided through ahigher layer signal such as an RRC message. The control channelcandidate number information will be described in detail later withreference to FIG. 16. Meanwhile, for example, when the BS fails toreceive UE capability information described above from the UE, the BSmay assume that the UE has capability of aggregating/scheduling certainCCs.

Example #A

In the case of a UE type in which BD capability is smaller than CAcapability, a reduction in the number of entire BDs for receiving an(E)PDCCH (at a specific SF point) may be considered to support largenumber of (DL) cell(s) with the limited BD capability. For example, theUE may reduce the number of predefined (or signaled) cell-related(E)PDCCH candidates or may perform scheduling on multiple cell(s) and/orSF(s) with one DCI.

Example #B

In cases where a lower peak rate (e.g., the entire number of softchannel bits(s)) against CA capability is considered, PDSCHreception-related (DL) soft buffer handling may be considered to supporta large number of (DL) cell(s) with a limited size of a soft buffer. Forexample, an operation of sharing a soft buffer between previouslyconfigured (or signaled) cell(s).

Example #C

In cases where a specific cell is configured (or signaled) tocross-carrier schedule (CCS) multiple cell(s) (from the point view ofone UE) or in cases where Pcell/scheduling cell are equally configured(or signaled) among multiple UE(s), an operation of sharing an SS (amongmultiple cell(s) or among multiple UE(s) may be considered to alleviatean increase in intra-UE (EPDCCH) blocking capability and/or inter-UE(E)PDCCH blocking probability due to simple concatenation (of multiplecell(s) or multiple UE(s)-related) search spaces (SSs).

Hereinafter, in order to support an increasing DL/UL data demand, amethod for effectively defining/operating a carrier indicator field(CIF) when a large number of cell(s) are configured through CA isproposed.

Here, for example, the following proposed rules may be configured to belimitedly applied only to some of various situations such as a casewhere a massive CA mode in which cells (carriers) more than five onesare aggregated is configured, a case where cell(s) (Lcell(s), Ucell(s),or (UL) Lcell(s)/Ucell(s)) are configured to be equal to or greater thana predefined (or signaled) number, a case where configured cell(s)(configured Lcell(s), configured Ucell(s), or configuredLcell(s)/Ucell(s)) are configured to be equal to or greater than apredefined (or signaled) number, a case where activated cell(s)(activated Lcell(s), activated Ucell(s), or activated Lcell(s)/Ucell(s))are configured to be equal to or greater than a predefined (or signaled)number, a case where the number of scheduled cell(s) configured in onescheduling cell is equal to or greater than a predefined (or signaled)threshold value, or a case where a cross carrier scheduling (CCS)technique is configured.

Before describing the proposed method in detail, a method fordesignating a (serving) cell index of each cell and a method fordesignating a (serving) cell index of each Scell will be described.

The BS provides an information element (IE) called “ServCellIndex” tothe UE. The “ServCellIndex” is a short identity used for identifying aserving cell such as a primary cell and a secondary cell and may haveany one integer value among 0 to 7. Here, value 0 is applied to theprimary cell, and the other values are applied to the secondary cell.

“SCellIndex” is a short identity used for identifying a secondary celland may have any one value among 1 to 7.

A related art carrier indication field (CIF) is set to be equal to aServCellIndex value or a SCellIndex value regarding a specific servingcell. For example, when a ServCellIndex value of a first serving cell is2, a CIF value indicating the first serving cell is also 2. In theexisting CA, a maximum of five CCs are aggregated and a CIF field has 3bits, and thus, 5 CCs are aggregated in CA and the CIF value and theServCellIndex value (or SCellIndex value) may be equally used. However,in future massive CA in which CCs more than 8 ones may be aggregated,each CC may not be properly indicated by the related art method.

Hereinafter, for the purposes of description, a (serving cellindex(ServCellIndex) of each cell will be referred to as “CIDX”, and a(serving) cell index(SCellIndex) of each Scell will be referred to as“SCIDX”.

[Proposed method #12] In cases where a CIF size is maintained (fixed) tothe same value as that of the related art, a CIF may be used on thebasis of (some or all of) the following rules. Here, for example, theexisting CIF size refers to 3 bit(s). Also, for example, application ofthe [proposed method #12] may be interpreted as limiting a maximumnumber of scheduled cell(s)CCS-ed from one scheduling cell to 5 or 8 (orTH_N).

Also, for example, a rule may be defined such that, when the [proposedmethod #12] is applied, a configuration/position of an SS related to aspecific (scheduled cell is determined on the basis of a CIDX (or SCIDX)of the corresponding (scheduled) cell (i.e., the CIDX (or SCIDX) of thespecific (scheduled) cell is substituted to an n_(CI) parameter), or arule may be defined such that, when the [proposed method #12] isapplied, a configuration/position of an SS related to a specific(scheduled cell is determined on the basis of a (re)mapped CIF value ofthe corresponding (scheduled) cell (i.e., a (re)mapped CIF value of aspecific (scheduled) cell is substituted to the n_(CI) parameter).

Also, for example, a rule may be defined such that, when the [proposedmethod #12] is applied, a PHR (power headroom report) mappingorder/position (of a MAC control element) related to a specific(scheduled) cell (and/or HARQ-ACK (and/or CSI) mapping order/position(of a PUCCH or PUSCH) are determined on the basis of the CIDX (or SCIDX)of the corresponding (scheduled) cell (or a rule is defined such that itis determined on the basis of a (re)mapped CIF value of thecorresponding (scheduled) cell).

(Rule #12-A) In cases where the number (referred to as “CONF_N”) ofcells configured for the UE is equal to or smaller than a predefined (orsignaled) threshold value (referred to as “TH_N”), a CIF value relatedto the specific (scheduled) cell may be assumed/configured to be equalto the CIDX (or SCIDX) value related to the corresponding (scheduled)cell. For example, TH_N may be set to 5 or 8. Also, for example, such arule may be applied when a CIF size and a size of the CIDX (or SCDIX)are equal. Here, the CIF size may have 3 bits and the CIDX (or SCDIX)may be set to have 3 bits.

(Rule#12-B) In cases where CONF_N is greater than TH_N, (re)mapping(CDIX (SCIDX)-to-CIF mapping) may be configured/performed between a CIDX(or SCIDX) value related to the specific (scheduled) cell and the CIFvalue related to the corresponding (scheduled) cell on the basis of(some or all of) the following methods.

For example, this method may be applied to a case where CONF_Nconfigured by CA is greater than a maximum number of (scheduled) cell(s)which can be indicated by the 3-bit CIF (or than a maximum number ofscheduled cell(s) which can be supported by the existing CCS. In thismanner, scheduled cell(s)CCS-ed from a specific scheduling cell may beeffectively indicated without changing a size of the existing CIF. Inother words, when such a method is applied, a CIF value related to aspecific (scheduled) cell and a CIDX (or SCIDX) value of thecorresponding (scheduled) cell may be different.

Also, for example, a rule may be defined such that (rule 12-B) is(limitedly) applied only to (scheduled) cell(s) having a CIDX (or SCIDX)value higher than a maximum number of (scheduled) cell(s) which may beindicated by the 3-bit CIF (or a maximum number of scheduled cell(s)which can be supported by the existing CCS). For example, CIDX-to-CIFmapping may be defined only for a CIF indicating cells having a value of8 or greater as a CIDX (or SCIDX).

Also, for example, application of such a rule may be interpreted suchthat a CIF size and a CIDX (or SCDIX) size are different (or that a CIDX(or SCDIX) size is greater than the CIF size). For example, the CIF sizemay be 3 bits and the CIDX (or SCDIX) size may be 5 bits.

Example#12-B-1

It may be configured through predefined signaling that to which CIFvalue scheduled cell(s)CCS-ed from a specific scheduling cell are to bemapped or re-mapped. Here, for example, the corresponding signaling maybe defined as physical layer signaling or higher layer signaling such asan RRC message.

In a specific example, in cases where 16 cell(s) (i.e., Cell (i.e.,PCELL) of CIDX 0, Scell of SCIDX 1, Scell of SCIDX 2, Scell of SCIDX 3,Scell of SCIDX 4, Scell of SCIDX 5, Scell of SCIDX 6, Scell of SCIDX 7,Scell of SCIDX 8, Scell of SCIDX 9, Scell of SCIDX 10, Scell of SCIDX 1,Scell of SCIDX 12, Scell of SCIDX 13, Scell of SCIDX 14, Scell of SCIDX15) are configured through CA, if cell(s) (i.e., scheduledcell(s))CCS-ed from the cell (i.e., scheduling cell) of CIDX 0) is setto Scell of SCIDX 1, Scell of SCIDX 3, Scell of SCIDX 1, and Scell ofSCIDX 12, (Scell of SCIDX 1, Scell of SCIDX 3) Scell of SCIDX 10 andScell of SCIDX 12 may respectively be (re)mapped to (CIF 1, CIF 3) CIF2, and CIF 4 (through predefined signaling). In other words, forexample, by (re)mapping CIF values of the scheduled Scell of SCIDX 10and scheduled Scell of SCIDX 12 to CIF 2 and CIF4, rather than to CIF10and CIF12, the scheduled Scell of SCIDX 10 and scheduled Scell of SCIDX12 CCS-ed from the scheduling cell of CIDX 0 may be effectivelyindicated without having to change the existing CIF size (i.e., 3 bits).

Example #12-B-2

It may be configured through a predefined rule that to which CIF valuescheduled cell(s) of CCS-ed from a specific scheduling cell are to be(re)mapped. In a specific example, a rule may be defined such that CIFvalues are (sequentially) (re)mapped to scheduled cell(s)CCS-ed from onescheduling cell in ascending order (or descending order) of CIDX (orSCIDX (or CG index)).

For example, it may be configured such that the CIF value of thescheduling cell may be set (or (re)mapped) to a predefined (or signaled)value (e.g., 0) and CIF values are (sequentially) (re)mapped only toscheduled cell(s)CCS-ed from the corresponding scheduling cell inascending order (or descending order) of CIDX (or SCIDX (or CG index)).Here, for example, the CIF values (re)mapped to the scheduled cell(s)refer to remaining CIF values excluding the CIF value (e.g., 0) relatedto the scheduling cell.

Also, in another example, it may be configured such that the CIF valueof the scheduling cell is set (or (re)mapped) to a predefined (orsignaled) value (e.g., 0) and the CIF values are (re)mapped only to thescheduled cell(s)CCS-ed from the corresponding scheduling cell by “CDIX(or SCIDX (or CG index)) modulo 8” or “CDIX (or SCIDX (or CG index))modulo 5”. N modulo M refers to the remainder obtained by dividing N byM.

Also, in another example, CIF values may (sequentially) be (re)mapped to(all of) a specific scheduling cell#X and scheduled cell(s)CCS-ed fromthe corresponding scheduling cell#X in ascending order (or descendingorder) of CIDX (or SCIDX (or CG index)). Or, CIF values may be(re)mapped by “CDIX (or SCIDX (or CG index)) modulo 8” or “CDIX (orSCIDX (or CG index)) modulo 5”.

Application of such a rule may be interpreted such that a CIF valuerelated to a scheduling cell and/or scheduled cell(s) and an (actual)CIDX (or SCIDX) value related to the corresponding scheduling celland/or scheduled cell(s) are different.

Example #12-B-3

A rule may be defined such that “CDIX (or SCDIX)-to-CIF value”(re)mapping information related to a scheduling cell and/or scheduledcell(s) is transferred (to a UE) through predefined signaling. Here, forexample, the corresponding information may be configured to be includedtogether and transmitted on (existing) RRC signaling providingCCS-related information.

[Proposed method #13] In cases where a CIF size is not maintained as (orfixed to) a value which is the same as an existing value, a CIF may beused on the basis of (some or all of) following rules. Here, forexample, the existing CIF size refers to 3 bit(s). Also, for example, arule may be defined such that, when the [proposed method #13] isapplied, a specific (scheduled) cell-related SS configuration/positionis determined on the basis of CIDX (or SCIDX) of the corresponding(scheduled) cell (that is, CIDX (or SCIDX) of the specific (scheduled)cell is substituted to a n_(CI) parameter) (or may be determined on thebasis of (re)mapped CIF value of the corresponding (scheduled) cell(i.e., the (re)mapped CIF value of the specific (scheduled) cell issubstituted to the n_(CI) parameter).

Also, for example, when the [proposed method #13] is applied, a rule maybe defined such that a mapping order/position of PHR (on a MAC controlelement) related to a specific (scheduled) cell (and/or a mappingorder/position of HARQ-ACK (and/or CSI) (on a PUCCH or PUSCH) aredetermined on the basis of a CIDX (or an SCIDX) of the corresponding(scheduled) cell or a rule may be defined such that it is determined onthe basis of a (re)mapped CIF value of the corresponding (scheduled)cell.

(Rule #13-A) In cases where the number of cells (hereinafter, referredto as “CONF_M”) set for the UE is equal to or smaller than a predefined(or signaled) threshold value (hereinafter, referred to as “TH_M”), aCIF size may be assumed/configured to have the same value (e.g., 3bit(s)) as an existing value.

Here, for example, TH_N may be set to 5 or 8. Also, for example, incases where (rule #13-A) is applied, a specific (scheduled) cell-relatedCIF value may be assumed/configured to be the same as the corresponding(scheduled) cell-related CIDX (or SCIDX) value.

Also, for example, application of such a rule may be interpreted suchthat the CIF size and a size of the CIDX (or SCIDX) are equal. Here, forexample, the CIF size may be set to 3 bits and a size of the CIDX (orSCIDX) may be set to 3 bits.

(Rule #13-B) In cases where CONF_N is greater than TH_N, a (mapping)relationship may be assumed/configured between the CIF size and/orspecific (scheduled) cell-related CIDX (or SCIDX) value and thecorresponding (scheduled) cell-related CIF value.

Example #13-B-1

The CIF size may be assumed/set to 5 bit(s). Here, for example, in caseswhere such a method is applied, the specific (scheduled) cell-relatedCIF value may be assumed/set to be the same as the corresponding(scheduled) cell-related CIDX (or SCIDX) VALUE.

Also, for example, application of such a rule may be interpreted suchthat the CIF size and the CIDX (or SCIDX) size are the same. Here, forexample, the CIF size may be set to 5 bits and the CIDX (or SCIDX) sizemay be set to 5 bits.

Example #13-B-2

The CIF size may be assumed/set to MAX{ceiling(log 2(number of scheduledcell(s) of each scheduling cell)), 3} by scheduling cells. Here, in theMAX {X, Y} function, a value which is relatively large or equal isderived from among X and Y, and in the ceiling (Z) function, a minimuminteger value which is greater than or equal to Z is derived.

When (example #13-B-2) is applied, a different CIF size may beapplied/assumed to (different) scheduled cell(s)CCS-ed from schedulingcell(s) having different number of scheduled cell(s).

When (example #13-B-2) is applied, (re)mapping may beconfigured/performed between the specific (scheduled) cell-related CIDX(or SCIDX) value and the corresponding (scheduled) cell-related CIFvalue on the basis of the (example #12-B-1) and/or the (example#12-B-2). Here, for example, through application of such a rule, incases where scheduled cell(s) larger than a maximum (scheduled) cell(s)which may be indicated by MAX{ceiling(log 2(number of scheduled cell(s)of each scheduling cell#X)), 3} bit-CIF from a view point of thespecific scheduling cell#X, scheduled cell(s)CCS-ed from thecorresponding scheduling cell#X may be effectively indicated.Application of such a rule may be interpreted such that the CIF size andthe CIDX (or SCIDX) size are different (or CIDX (or SCIDX) is greaterthan the CIF size). Here, for example, the CIF size may be 3 bits andthe CISX (or SCIDX) size may be set to 5 bits.

Example #13-B-3

The CIF size may be assumed/set to ceiling(log 2(number of scheduledcell(s))). When the (example #13-B-3) is applied, a different CIF sizemay be applied/assumed to (different) scheduled cell(s)CCS-ed fromscheduling cell(s) having a different number of scheduled cell(s).

When the (example #13-B-3) is applied, (re)mapping may beconfigured/performed between the specific (scheduled) cell-related CIDX(or SCIDX) value and the corresponding (scheduled) cell-related CIFvalue on the basis of the (example #12-B-1) and/or the (example#12-B-2). Here, for example, by applying such a rule, when a greaternumber of scheduled cell(s) than a maximum number of (scheduled) cell(s)which may be indicated by a ceiling (log 2)Number of scheduled cell(s))bit-CIF are configured as CCS, scheduled cell(s)CCS-ed from thecorresponding scheduling cell#X may be effectively indicated.

Also, for example, application of such a rule may be interpreted suchthat a CIF size and a CIDX (or SCIDX) size are different (or the CIDX(or SCIDX) size is greater than the CIF size). Here, for example, theCIF size may be set to 3 bits and the CIDX (or SCDIX) size may be set to5 bits.

Example #13-B-4

A CIF size may be assumed/set to MAX{ceiling(log 2(number of configuredcells)), 3} or ceiling(log 2(number of configured cells))

[Proposed method #17] In cases where the CIF size is maintained as (orfixed to) a value which is the same as the existing value, the CIF maybe used on the basis of (some or all) of the following rules. Theexisting CIF size is meant to be 3 bit(s).

Application of the [proposed method #17] may be interpreted such that amaximum number of scheduled cell(s)CCS-ed from one scheduling cell islimited to 5 or 8.

Also, a rule may be defined such that, when the [proposed method #17] isapplied, a configuration/position of an SS related to a specific(scheduled cell is determined on the basis of a CIDX (or SCIDX) of thecorresponding (scheduled) cell (i.e., the CIDX (or SCIDX) of thespecific (scheduled) cell is substituted to an n_(CI) parameter). Or, arule may be defined such that, when the [proposed method #12] isapplied, a configuration/position of an SS related to a specific(scheduled cell is determined on the basis of a (re)mapped CIF value ofthe corresponding (scheduled) cell (i.e., a (re)mapped CIF value of aspecific (scheduled) cell is substituted to the n_(CI) parameter).

Also, when the [proposed method #17] is applied, a PHR (power headroomreport) mapping order/position (of a MAC control element) related to aspecific (scheduled) cell (and/or HARQ-ACK (and/or CSI) mappingorder/position (of a PUCCH or PUSCH) may be determined on the basis ofthe CIDX (or SCIDX) of the corresponding (scheduled) cell, or may bedetermined on the basis of a (re)mapped CIF value of the corresponding(scheduled) cell). Also, for example, a rule may be defined such thatthe [proposed method #17] is limitedly applied only to a case where amassive CA mode is configured, a case where cell(s) (Lcell(s), Ucell(s),or Lcell(s)/Ucell(s)) are configured to be equal to or greater than apredefined (or signaled) number (or a case where configured cell(s)(configured Lcell(s), configured Ucell(s), or configuredLcell(s)/Ucell(s)) are configured to be equal to or greater than apredefined (or signaled) number), a case where activated cell(s)(activated Lcell(s), activated Ucell(s), or activated Lcell(s)/Ucell(s))are configured to be equal to or greater than a predefined (or signaled)number, and/or a case where the number of scheduled cell(s) configuredin one scheduling cell is equal to or greater than a predefined (orsignaled) threshold value.

The existing (REL-12 LTE) operation may be applied to a case where themassive CA mode is not configured, a case where cell(s) (Lcell(s),Ucell(s), or Lcell(s)/Ucell(s)) are configured to be smaller than apredefined (or signaled) number, a case where configured cell(s)(configured Lcell(s), configured Ucell(s) (or configuredLcell(s)/Ucell(s)) are configured to be smaller than a predefined (orsignaled) number), a case where activated cell(s) (activated Lcell(s),activated Ucell(s), or activated Lcell(s)/Ucell(s)) are configured to besmaller than a predefined (or signaled) number, and/or a case where thenumber of scheduled cell(s) configured in one scheduling cell is smallerthan a predefined (or signaled) threshold value.

(Rule #17-A) (Re)mapping (CDIX (SCIDX)-to-CIF mapping) may beconfigured/performed between a CIDX (or SCIDX) value related to thespecific (scheduled) cell and the CIF value related to the corresponding(scheduled) cell on the basis of (some or all of) the following methods(regardless of the number of configured cell(s) (hereinafter, referredto as “CONF_N”)).

Application of such a rule may be interpreted such that a CIF size and aCIDX (or SCDIX) size are different (or that a CIDX (or SCDIX) size isgreater than the CIF size). Here, for example, the CIF size may be setto 3 bits and the CIDX (or SCDIX) size may be set to 5 bits.

Also, for example, this method may be applied to a case where CONF_Nconfigured by CA is greater than a maximum number of (scheduled) cell(s)which can be indicated by the 3-bit CIF (or than a maximum number ofscheduled cell(s) which can be supported by the existing CCS, wherebyscheduled cell(s)CCS-ed from a specific scheduling cell may beeffectively indicated (without changing a size of the existing CIF). Inother words, when such a method is applied, a CIF value related to aspecific (scheduled) cell and an (actual) CIDX (or SCIDX) value relatedto the corresponding (scheduled) cell may be different. Also, the (rule17-A) may be (limitedly) applied only to (scheduled) cell(s) having aCIDX (or SCIDX) value higher than a maximum number of (scheduled)cell(s) which may be indicated by the 3-bit CIF (or a maximum number ofscheduled cell(s) which can be supported by the existing CCS). Forexample, CIDX-to-CIF mapping may be defined only for a CIF indicatingcells having a value of 8 or greater as a CIDX (or SCIDX).

Example #17-A-1

It may be configured through predefined signaling that to which CIFvalue scheduled cell(s)CCS-ed from a specific scheduling cell are to bere-mapped. Here, for example, the corresponding signaling may bephysical layer signaling or higher layer signaling (e.g., RRCsignaling). Here, for example, the CIF values (re)mapped to thescheduled cell(s) may be configured (or limited) to remaining CIF valuesexcluding the (fixed) CIF value (e.g., 0) related to the schedulingcell.

FIG. 11 illustrates an operation method of a UE according to theaforementioned rule #17-A or example #17-A-1.

Referring to FIG. 11, a BS transmits, to a UE, a higher layer signalindicating mapping between ServingCellID (or SCellID) and a carrierindex field (CIF) (S610). Here, the mapping will be described in detailwith reference to FIG. 12 hereinafter. The higher layer signal may be anRRC message.

Here, for example, the higher layer signal indicating mapping betweenServingCellID (or SCellID) and a CIF is aimed at only scheduled cell(s),and a CIF value of a scheduling cell may be set (or mapped) to apredefined (or fixed or signaled) value (e.g., 0). That is, in caseswhere cell #A is a scheduling cell which transmits schedulinginformation of other cells and cells #B and #C are cells scheduled bythe scheduling information from the cell #A, mapping betweenServingCellID and a CIF may indicating only mapping betweenServingCellID of the cells #B and #C and a CIF value. That is, thehigher layer signal does not provide mapping between ServingCellID and aCIF for the cell #A, a scheduling cell, and a predetermined or fixed CIFvalue (e.g., 0) is always allocated (mapped) to the cell #A.

Or, the higher layer signal may indicated mapping between ServingCellIDregarding the cell #A and a CIF value, and here, a fixed value (e.g., 0)may be always mapped to the cell #A.

The higher layer signal may be provided through the cell #a or may beprovided through any other cell than the cell #A.

The BS transmits downlink control information (DCI) including a CIF(S620).

The UE identifies a cell indicated by the CIF on the basis of themapping (S630).

In FIG. 11, an example in which a cell indicated by the CIF included inthe DCI is identified on the basis of the higher layer signal indicatingmapping between ServingCellID and the CIF, but the present disclosuremay also be applied to any other cases.

The UE may receive the DCI including the CIF, and receives or transmitsdata on the basis of the DCI in a serving cell indicated by the CIF.Here, the serving cell indicated by the CIF may be identified on thebasis of the higher layer signal indicating mapping between the servingcell index (ServingCellID) of the serving cell and the CIF value (in thecase of scheduled cell(s)). Also, in the case of a scheduling cell, itis identified on the basis of a (mapping) relationship between thepredefined (or fixed or signaled) serving cell index (ServingCellID) ofthe serving cell and the CIF value (e.g., 0). For example, as describedabove, the CIF may consist of 3 bits and have one of values from 0 to 7,and the serving cell index may have one of values from 0 to 31.

For example, more than five serving cells may be allocated to the UE.Here, the CIF value indicating the serving cell may be set to a valuewhich is not the same as the serving cell index (ServingCellID) of theserving cell by the mapping. Here, for example, mapping between theserving cell index (ServingCellID) of the serving cell and the CIF valuemay be configured by a higher layer signal indicating mapping betweenthe serving cell index (ServingCellID) of the serving cell and the CIFvalue (in the case of scheduled cell(s)) (and/or may be configured by a(mapping) relationship between the predefined (or fixed or signaled)serving cell index (ServingCellID) of the serving cell and the CIF value(e.g., 0) (in the case of a scheduling cell)).

FIG. 12 illustrates mapping between ServingCellID (or SCellID) and aCIF.

Referring to FIG. 12, it is illustrated that a cell (i.e., Pcell) of aserving cell index (indicated by ServingCellID) 0 and Scells of servingindices 1 to 9 are aggregated/configured to the UE. Also, it isillustrated that Scells having serving cell indices 1, 3, 4, 5, 6, 8,and 9, as well as the Pcell (i.e., serving cell index 0) (i.e.,self-scheduling), are cross-carrier scheduled (CCS-ed) on the Pcell.

Here, the BS transmits a higher layer signaling indicating mappingbetween a serving cell ID (ServingCellID) of a cell scheduled throughthe higher layer signal and a CIF. For example, the UE may be informedthat the CIF values 1, 2, 3, 4, 5, 6, and 7 are sequentially mapped orremapped to serving cell indices 1, 3, 4, 5, 6, 8, and 9 (e.g.,scheduled cell(s)). Here, for example, a predefined (or fixed orsignaled) CIF value 0 is mapped to the Pcell, a scheduling cell, (i.e.,serving cell index 0). That is, CIDX-to-CIF mapping is not provided tothe Pcell, a scheduling cell, and a previously fixed/predetermined value(e.g., 0) may be used or a certain CIF value (e.g., 0) may be mapped ifCIDX-to-CIF mapping is provided.

For example, when the UE receives DCI having a CIF value 6 is receivedin the Pcell, the DCI may be recognized as scheduling informationregarding a cell having a serving cell index 8. Thus, cross-carrierscheduling may be performed in CA in which more than eight cells areaggregated, without having to change a size of the 3-bit CIF.

In a specific example, in cases where 16 cell(s) (i.e., Cell (i.e.,PCELL) of CIDX 0, Scell of SCIDX 1, Scell of SCIDX 2, Scell of SCIDX 3,Scell of SCIDX 4, Scell of SCIDX 5, Scell of SCIDX 6, Scell of SCIDX 7,Scell of SCIDX 8, Scell of SCIDX 9, Scell of SCIDX 10, Scell of SCIDX 1,Scell of SCIDX 12, Scell of SCIDX 13, Scell of SCIDX 14, Scell of SCIDX15) are configured through CA, if cell(s) (i.e., scheduledcell(s))CCS-ed from the cell (i.e., scheduling cell) of CIDX 0) is setto Scell of SCIDX 1, Scell of SCIDX 3, Scell of SCIDX 1, and Scell ofSCIDX 12, (Scell of SCIDX 1, Scell of SCIDX 3) Scell of SCIDX 10 andScell of SCIDX 12 may respectively be (re)mapped to (CIF 1, CIF 3) CIF2, and CIF 4 (through predefined signaling). In other words, forexample, by (re)mapping CIF values of the scheduled Scell of SCIDX 10and scheduled Scell of SCIDX 12 to CIF 2 and CIF4, rather than to CIF10and CIF12, the scheduled Scell of SCIDX 10 and scheduled Scell of SCIDX12 CCS-ed from the scheduling cell of CIDX 0 may be effectivelyindicated without having to change the existing CIF size (i.e., 3 bits).

Example #17-A-2

It may be configured through a predefined rule that to which CIF valuescheduled cell(s) of CCS-ed from a specific scheduling cell are(re)mapped. In a specific example, a rule may be defined such that CIFvalues are (sequentially) (re)mapped (or CIF values are (re)mappedaccording to (example #17-A-1) to scheduled cell(s)CCS-ed from onescheduling cell in ascending order (or descending order) of CIDX (orSCIDX (or CG index)). Here, for example, it may be configured such thatthe CIF value of the scheduling cell may be set (or (re)mapped) to apredefined (or signaled) value (e.g., 0) and CIF values are(sequentially) (re)mapped (or CIF values are (re)mapped according to(example #17-A-1) only to scheduled cell(s)CCS-ed from the correspondingscheduling cell in ascending order (or descending order) of CIDX (orSCIDX (or CG index)).

For example, the CIF values (re)mapped to the scheduled cell(s) mayrefer to remaining CIF values excluding the CIF value (e.g., 0) relatedto the scheduling cell. Here, in another example, it may be configuredsuch that the CIF value of the scheduling cell is set (or (re)mapped) toa predefined (or signaled) value (e.g., 0) and the CIF values are(re)mapped only to the scheduled cell(s)CCS-ed from the correspondingscheduling cell by “CDIX (or SCIDX (or CG index)) modulo 8” or “CDIX (orSCIDX (or CG index)) modulo 5”.

Also, in another example, CIF values may (sequentially) be (re)mapped to(all of) a specific scheduling cell#X and scheduled cell(s)CCS-ed fromthe corresponding scheduling cell#X in ascending order (or descendingorder) of CIDX (or SCIDX (or CG index)) (or, CIF values are (re)mapped(or CIF values are (re)mapped according to (example #17-A-1)) by “CDIX(or SCIDX (or CG index)) modulo 8” or “CDIX (or SCIDX (or CG index))modulo 5”.

Application of such a rule may be interpreted such that a CIF valuerelated to a scheduling cell and/or scheduled cell(s) and an (actual)CIDX (or SCIDX) value related to the corresponding scheduling celland/or scheduled cell(s) are different.

Example #17-A-3

“CDIX (or SCDIX)-to-CIF value” (re)mapping information related to ascheduling cell and/or scheduled cell(s) may be transferred (to a UE)through predefined signaling (e.g., RRC signaling). For example, thecorresponding information may be included together and transmitted on(existing) RRC signaling providing CCS-related information.

[Proposed method #18] When a cell group (CG) of cell(s) (including (ornot including) CELL_PUCCH) interworking with a specific cell(hereinafter, referred to as “CELL_PUCCH”) in which PUCCH transmissionis configured (or allowed) is referred to as “PUCCH_CG”, a CIF sizerelated to CCS configured between corresponding PUCCH_CG configurationcell(s) may be changed according to the number of cells constituting thecorresponding PUCCH_CG.

The CIF size may be determined as “MAX{ceiling(log 2(number of cells(including (or not including) CELL_PUCCH) constituting PUCCH_CG)), 3}”or “CEILING(log 2(number of cells (including (or not including)CELL_PUCCH) constituting PUCCH_CG))”

For example, in cases where the former rule is applied, if a specificPUCCH_CG#X includes 8 cell(s) (including (or not including) CELL_PUCCH),a CIF size related to a CCS configured between the correspondingPUCCH_CG#X configuration cell(s) may be determined to 3 bit(s), and if aspecific PUCCH_CG#Y includes 24 cell(s) (including (or not including)CELL_PUCCH), a CIF size related to a CCS configured between the cell(s)forming the corresponding PUCCH_CG#Y may be determined to 5 bit(s).

In another example, in cases where the number of cells (including (ornot including) CELL_PUCCH) forming the PUCCH_CG is equal to or smallerthan a predefined (or signaled) threshold value (e.g., 5 or 8), the CIFsize may be determined to be equal to the existing value (e.g., 3 bit(s)or “MAX{ceiling(log 2(number of cells forming PUCCH_CG)), 3}”, and incases where the number of cells (including (or not including)CELL_PUCCH) forming the PUCCH_CG is greater than a predefined (orsignaled) threshold value (e.g., 5 or 8), the CIF size may be determinedas 5 bit(s) or “CEILING(log 2(number of cells forming PUCCH_CG))”.

Also, for example, when the [proposed method #18] is applied, theaforementioned (re)mapping (CDIX (SCDIX)-to-CIP mapping) rule may beadditionally applied to the specific (scheduled) cell-related CIDX (orSCIDX) value and the corresponding (scheduled) cell-related CIF value toeffectively manage/control the specific (scheduled) cell-related SSconfiguration/position, PHR mapping order/position (on the MAC controlelement), and/or HARQ-ACK (and/or CSI) mapping order/position (on aPUCCH or PUSCH).

In another example, the [proposed method #18] may be limitedly appliedonly to a case where a massive CA mode is configured, a case where anScell (or Lcell (or Ucell)) is configured as CELL_PUCCH, a case whereCELL_PUCCH (or PUCCH_CG) is configured to be equal to or greater than apredefined (or signaled) number, a case where cell(s) (Lcell(s),Ucell(s), or (UL) Lcell(s)/Ucell(s)) (forming the PUCCH_CG) areconfigured to be equal to or greater than a predefined (or signaled)number (or a case where configured cell(s) (configured Lcell(s),configured Ucell(s), or configured Lcell(s)/Ucell(s)) are configured tobe equal to or greater than a predefined (or signaled) number), a casewhere activated cell(s) (activated Lcell(s), activated Ucell(s), oractivated Lcell(s)/Ucell(s)) (forming the PUCCH_CG) are configured to beequal to or greater than a predefined (or signaled) number, and/or acase where the number of scheduled cell(s) configured in one schedulingcell (forming the PUCCH_CG) is equal to or greater than a predefined (orsignaled) threshold value (and/or a CCS is limitedly configured onlybetween PUCCH_CG configuration cell(s)).

Here, the existing (REL-12 LTE) operation may be applied to a case wherethe massive CA mode is not configured, a case where an Scell (or Lcell(or Ucell)) is not configured as CELL_PUCCH, a case where CELL_PUCCH (orPUCCH_CG) is configured to be smaller than a predefined (or signaled)number, a case where cell(s) (Lcell(s), Ucell(s), or (UL)Lcell(s)/Ucell(s)) are configured to be smaller than a predefined (orsignaled) number, a case where configured cell(s) (configured Lcell(s),configured Ucell(s) (or configured Lcell(s)/Ucell(s)) are configured tobe smaller than a predefined (or signaled) number), a case whereactivated cell(s) (activated Lcell(s), activated Ucell(s), or activatedLcell(s)/Ucell(s)) (forming the PUCCH_CG) are configured to be smallerthan a predefined (or signaled) number, and/or a case where the numberof scheduled cell(s) configured in one scheduling cell (forming thePUCCH_CG) is smaller than a predefined (or signaled) threshold value(and/or a CSS is configured (allowed) even between different PUCCH_CGconfiguration cell(s)).

Hereinafter, downlink control information (DCI), a search space (SS) formonitoring/detecting DCI, and a method for configuring an aggregationlevel (AL) and blind decoding (BD) in an SS in a wireless communicationsystem supporting aggregation of a plurality of cells (carriers) will bedescribed. For example, the existing CA supports only aggregation of amaximum of 5 cells, but future CA may support aggregation of a maximumof 32 cells. The present disclosure may be applied to a UE supportingthe future CA. However, although the UE supporting future CA may alsonaturally support aggregation of 5 or less cells, to which the presentdisclosure may also be applied.

For example, in an environment in which a large number of cell(s) areconfigured by CA, in order to reduce overhead of (DL/UL) schedulinginformation transmissions related to the corresponding cell(s),scheduling information related to a plurality of previously configured(or signaled) cell(s) may be transmitted through single DCI (or acontrol channel) (hereinafter, referred to as “MUCC-DCI”). That is, theMUCC-DCI refers to single DCI including scheduling information relatedto the plurality of cells.

Here, for example, cells simultaneously scheduled through the MUCC-DCImay be configured (or limited) to the same cell type, TM, systembandwidth, communication type, and/or cell(s) of a CG. Here, forexample, the cell type refers to Ucell or Lcell, and the communicationtype refers to FDD or TDD. Hereinafter, for the purposes of description,DCI (or a control channel) in which one cell-related schedulinginformation is transmitted (as in the related art) will be referred toas “SICC-DCI”.

FIG. 13 illustrates an SICC-DCI and a MUCC-DCI.

Referring to FIG. 13, cells #N and #K represent two of a plurality ofcells configured in the same UE. The SICC-DCI transmitted in the cell #Nis DCI including scheduling information regarding one cell, e.g., thecell #N. Meanwhile, the MUCC-DCI transmitted in the cell #N is DCIincluding scheduling information regarding a plurality of cells, e.g.,the cells #N and #K. In FIG. 13, an example in which both the SICC-DCIand the MUCC-DCI are transmitted in a PDCCH region, but the presentdisclosure is not limited thereto and both the SICC-DCI and the MUCC-DCImay be transmitted in an EPDCCH region, or only the MUCC-DCI (or onlythe SICC-DCI) may be transmitted in the EPDCCH region (or a PDCCHregion). Also, in FIG. 12, DL scheduling is illustrated but ULscheduling is not different.

Hereinafter, methods for determining/configuring a length (size) of theSICC-DCI/MUCC-DCI and/or an SS in which the SICC-DCI/MUCC-DCI aretransmitted will be described.

[Proposed method #14] A rule may be defined such that SICC-DCI size(s)related to a plurality of previously configured (or signaled) cell(s) asa target of the MUCC-DCI are set (or adjusted) to be equal to acorresponding MUCC-DCI size. That is, if cells as targets of theMUCC-DCI are cells #1, #2, and #3, an SICC-DCI regarding the cell #1, anSICC-DCI regarding the cell #2, and an SICC-DCI regarding the cell #3are configured to have a length equal to that of the MUCC-DCI. If aSICC-DCI size related to a specific cell as a target of the MUCC-DCI issmaller than the MUCC-DCI size, zero padding may be applied to theSICC-DCI until the SICC-DCI size is equal to the corresponding MUCC-DCIsize. Through application of this method, an increase in the number ofBD may be prevented when BD is simultaneously performed on the MUCC-DCIand the SICC-DCI.

Also, for example, SICC-DCI size(s) related to a plurality of(predefined (or signaled)) cells(s) as a target of the MUCC-DCI may beadjusted to a longest size or a shortest size among the SICC-DCI size(s)related to the plurality of corresponding cell(s). Or, a rule may bedefined such that SICC-DCI size(s) related to a plurality of (predefined(or signaled)) cells(s) as a target of the MUCC-DCI are configured to beequal to a SICC-DCI size related to a previously configured (orsignaled) specific cell or a previously configured (or signaled) DCIsize. Through application of this method, an increase in the number ofBD required for BD of SICC-DCI(s) related to a plurality of (previouslyconfigured (or signaled)) cell(s) as a target of the MUCC-DCI on onesubframe may be prevented.

[Proposed method #15] The SICC-DCI size(s) related to a plurality ofpreviously configured (or signaled) cell(s) as a target of the MUCC-DCImay be transmitted on a single common search space (or a shared SS).

The corresponding shared SS may be configured in a cell having lowest(or highest) CIDX (or SCIDX), a previously configured (or signaled)specific cell, or a cell configured for PUCCH transmission, among theplurality of (previously configured (or signaled)) cell(s) as a targetof the MUCC-DCI.

Or the shared SS may be configured on the basis of a previouslyconfigured (or signaled) CIF value (and/or RNTI value), rather than CIDX(or SCIDX or CIF value) of the cell for which the shared SS isconfigured) (please refer to the aforementioned [proposed method #1]).

Also, for example, a CIF may be newly defined in the SICC-DCI related toa specific cell as a target of the MUCC-DCI transmitted in thecorresponding shared SS, and also, the corresponding CIF value may bedefined as a CIDX (or SCIDX) of the specific cell (or a CIF value(re)mapped according to the [proposed method #12]/[proposed method #13].

Also, for example, the corresponding MUCC-DCI may be transmitted(together) in the shared SS in which the SICC-DCI(s) related to theplurality of (previously configured (or signaled)) cell(s) as a targetof the MUCC-DCI.

Here, for example, the corresponding MUCC-DCI may be blind-decoded onthe basis of a previously (newly) configured or signaled RNTI valueunlike the SICC-DCI blind-decoded on the basis of a C-RNTI, or may beblind-decoded on the basis of the C-RNTI like the SICC-DCI.

Also, for example, the MUCC-DCI may be transmitted in an SS of apredefined (or signaled) different cell, rather than in the shared SS inwhich the SICC-DCI(s) related to a plurality of (predefined (orsignaled)) cell(s) as a target of the MUCC-DCI, or may be transmitted inan SS configured on the basis of a previously (newly) defined (orsignaled) CIF value (and/or RNTI value), rather than a CIDX (or SCIDX orCIF value) of the cell in the cell for which the corresponding shared SShas been configured.

Also, for example, the MUCC-DCI may be transmitted in an SS of a cellhaving a lowest (or highest) CIDX (or SCIDX) (or an SS of a predefined(or signaled) specific cell or an SS of a cell for which PUCCHtransmission has been configured), among a plurality of predefined (orsignaled) cell(s) as a target of the MUCC-DCI.

Also, for example, the MUCC-DCI may be transmitted in an SS of apredefined (or signaled) different cell, rather than the plurality ofpredefined (or signaled) cell (s) as a target of the MUCC-DCI.

Here, in another example, the corresponding different cell in which theMUCC-DCI is transmitted may be designated (or interpreted) as anMUCC-DCI transmission-dedicated cell (hereinafter, referred to as“CELL#MX”). Also, for example, the MUCC-DCI(s) transmitted in theCELL#MX may also be transmitted in (CELL#MX) SS(s) configured on thebasis of cell group index(s) as a target of the correspondingMUCC-DCI(s).

[Proposed method #16] AL candidate configuration related to MUCC-DCI andSICC-DCI blind decoding (performed in one subframe (according to theaforementioned [proposed method #12] to [proposed method #15]) and/orthe number of BD per AL may be configured to be different.

The proposed method #16 considers that the MUCC-DCI (payload) size maybe generally greater than a SICC-DCI (payload) size. Through applicationof the proposed method #16, it is possible to adaptively configure ALcandidates in consideration of the MUCC-DCI (payload) size and/or setthe number of BD of each AL, and eventually, reliability of MUCC-DCItransmission may be increased.

In a specific example, AL candidates related to SICC-DCI and MUCC-DCIblind decoding may be ({AL 1, AL 2, AL 4, AL 8}, {AL 4, AL 8}) or ({AL1, AL 2, AL 4, AL 8}, {AL 2, AL 4, AL 8, AL 16}). In the mark ({ }, {}), the former { } indicates an AL candidate of the SICC-DCI and thelatter { } indicates an AL candidate of the MUCC-DCI. This may beinterpreted such that the MUCC-DCI is blind-decoded on the basis of ALcandidates higher than those of the SICC-DCI. Or, AL candidates relatedto SICC-DCI and MUCC-DCI blind decoding may be ({AL 1, AL 2, AL 4, AL8}, {AL 1, AL 2}). This may be interpreted such that the MUCC-DCI isblind-decoded on the basis of AL candidates lower than those of theSICC-DCI.

Also, in another example, (some or all of) the number of BD ofpredefined (or signaled) AL(s) lower (than those of the SICC-DCI) may bere-allocated to the higher number of BD of AL(s)

In a specific example, in cases where BD number is re-allocated in asituation in which the number of BD of each ‘AL {1, 2, 4, 8}’ related tothe SICC-DCI is defined as ‘BD {6, 6, 2, 2}’, the number of BD of each‘AL {1, 2, 4, 8}’ related to the MUCC-DCI may be changed to ‘BD {4, 4,4, 4}’ (that is, the number of BD as twice regarding the existing AL ‘1’is re-allocated as AL‘4’ and the number of BD as twice regarding theexisting AL ‘2’ is re-allocated as AL‘8’). Or, the number of BD of each‘AL {1, 2, 4, 8}’ may be changed to ‘BD {2, 6, 6, 2}’ (that is, thenumber of BD as four times of the existing AL‘1’ is re-allocated asAL‘4’) or may be changed to ‘BD {0, 6, 6, 4}’ (that is, in the number ofBD as a total of six times of the existing AL, the number of BD as fourtimes is re-allocated as AL‘4’ and the number of BD as twice isre-allocated to AL‘8’.

Also, in another example, to ensure reliable transmission/reception ofthe MUCC-DCI, (MUCC-DCI detection-related) minimum AL value and/or thenumber of (E)REGs forming one (E)CCE, and the like, may be (re)defined.In a specific example, in a situation in which the number of BD of each‘AL {1, 2, 4, 8}’ is defined as ‘BD {6, 6, 2, 2}’, when the rule isapplied, the minimum AL value is increased from ‘1’ to ‘2’, whereby theAL set having the number of BD of ‘BD {6, 6, 2, 2}’ may be changed to‘AL {2, 4, 8, 16}’. It may be configured such that (total) number of BDis maintained in cases where it is sufficient to support a plurality ofAL(s) having a relatively large amount of resource in an (E)PDCCH. Or,an Al set having the number of BD of ‘BD {3, 3, 1, 1}’ may be changed to‘AL {2, 4, 8, 16}’. That is, it may be configured such that (total)number of BD is reduced (to half) in cases where it is not sufficient tosupport a plurality of AL(s) having a relatively large amount ofresource in the (E)PDCCH.

Also, in another example, when the rule is applied, the number of(E)REGs forming one (E)CCE may be changed from ‘4’ to ‘8’.

[Proposed method #20] Scheduling information based on the DCI format 1Arelated to a plurality of previously configured (or signaled) cell(s)according to (some of all) of the aforementioned proposed methods (e.g.,according to the [proposed method #12] to [proposed method #16] istransmitted through (one) MUCC-DCI (hereinafter referred to as “MUCC-DCI1A”), a DCI format 0 size (i.e., SICC-DCI) related to corresponding eachcell may be configured to be smaller than a DCI format 1A size (i.e.,SICC-DCI) related to each cell (through predefined rule or signaling)

Meanwhile, in the case of existing LTE system, the DCI format 0 size andDCI format 1A size (transmitted in the same SS) related to a specificcell are always equal. That is, among the DCI format 0 and the DCIformat 1A, a DCI format having a (relatively small size) is adjusted toa DCI format having a (relatively) large size through zero padding.

By applying the proposed method, a probability of DCI format 0 falsedetection related to the plurality of cell(s) configured by the MUCC-DCI1A. Here, for example, the DCI format 0 size may be reduced by omittingpreviously defined (or signaled) field(s) (e.g., a “FLAG FORFORMAT0/FORMAT1A DIFFERENTIAION’ field, a field for differentiating DCIformat 0/1A.

[Proposed method #21] When the [proposed method #20] is applied (or whenthe UE receives (/detects) a DCI format 1A (i.e., SICC-DCI) related tospecific cell(s) in which MUCC-DCI 1A is configured (in cases where the[proposed method #20] is applied (or regardless of application of the[proposed method #20]), the UE may regard the correspondingreceived(/detected) DCI format 1A (i.e., SICC-DCI) as false detection.

Also, in another example, a rule may be defined such that, if the UEsimultaneously receives (/detects) the DCI format 1A (i.e., SICC-DCI)related to the specific cell(s) in which the MUCC-DCI 1A is established,and the MUCC-DCI 1A, the UE may regard the corresponding received(/detected) DCI format 1A (i.e., SICC-DCI) (and/or the MUCC-DCI 1A) asfalse detection and discard the MUCC-DCI 1A and the DCI format 1A, ordiscard only the DCI format 1A and regard the MUCC-DCI 1A as valid ormay discard only the MUCC-DCI 1A and regard the DCI format 1A as valid.

[Proposed method #23] The MUCC-DCI may be limitedly used for the purposeof transmitting only DL grant(s) (rather than (UL grant(s) related to aplurality of previously configured (or signaled) cell(s)), through oneDCI (or control channel). This obtains a reduction in BD.

In another example, the MUCC-DCI may be limitedly used for the purposeof transmitting only UL grant(s) (rather than (DL grant(s) related to aplurality of previously configured (or signaled) cell(s)), through oneDCI (or control channel). This also obtains a reduction in BD.

[Proposed method #24] In order to reduce “false detection probability”related to DCI format (reception), CRC size extension may be considered.The corresponding “CRC size extension” may be limitedly applied only toDL grant(s) (rather than UL grant(s)). Or, the “CRC size extension”operation may be limitedly applied only to UL grant(s) (rather than (DLgrant(s)).

FIG. 14 illustrates an operation method of a UE when the proposed method#14, proposed method #15, proposed method #16, proposed method #20,proposed method #21, proposed method #23, and proposed method #24described above are applied.

Referring to FIG. 14, the BS provides MUCC-DCI configuration informationto the UE (S100). For example, for the MUCC-DCI configurationinformation, at least one of the following matters may be configured.

1) A size of the SICC-DCI related to a plurality of cells as a target ofthe MUCC-DCI is configured to be equal to a size of the MUCC-DCI (pleaserefer to the proposed method #14)

2) A cell and a search space in which the MUCC-DCI can be transmittedare configured (please refer to the proposed method #15)

3) An aggregation level (AL) candidate related to blind decoding (BD)regarding the MUCC-DCI and the SICC-DCI performed on one subframe isconfigured and/or the number of BD for each AL is set (please refer tothe proposed method #16)

For example, the MUCC-DCI configuration information may inform about aserving cell in which the shared SS is positioned, among a plurality ofserving cells.

The BS transmits the MUCC-DCI to the UE (S110). Here, the BS maytransmit the MUCC-DCI in consideration of a cell to be configured forthe UE through the MUCC-DCI information, an SS, a configuration of an ALcandidate, setting the number of BD, and the like. As described above,single MUCC-DCI may include a plurality of pieces of control informationfor scheduling one serving cell.

The UE detects/monitors the MUCC-DCI from the shared SS determinedaccording to the MUCC-DCI configuration information (S120).Rules/configurations to be considered in detecting/monitoring theMUCC-DCI have already been described above in the proposed methods #20,#21, #23, and #24.

For example, the MUCC-DCI and the SICC-DCI, DL control information forscheduling one serving cell may be configured to have the same bit sizein the shared SS. Also, for example, when the MUCC-DCI is used only forDL grant, monitoring for detecting UL grant may be unnecessary.

Also, if a CRC size of the MUCC-DCI is increased, relative to theexisting SICC-DCI, the MUCC-DCI may be monitoring in consideration ofthe increase in the CRC size of the MUCC-DCI. Also, the UE mayblind-decode only the MUCC-DCI which may include scheduling informationrelated to a plurality of serving cells or may blind-decode both theMUCC-DCI and the SICC-DCI in the shared SS.

Al candidates when blind-decoding is performed on the MUCC-DCI and ALcandidates when blind decoding is performed on the SICC-DCI, DL controlinformation for scheduling one serving cell may be configured to bedifferent. The number of BD in each AL when blind-decoding is performedon the MUCC-DCI and the number of BD in each AL when blind decoding isperformed on the SICC-DCI may be set to be different. In each AL, thenumber of BD previously determined for the MUCC-DCI may bereset/re-allocated. Details thereof have described above (e.g., theproposed method #16). Also, blind decoding may be performed on thepremise that a cyclic redundancy check (CRC) longer than the SICC-DCI,DL control information for scheduling one serving cell, can be added tothe MUCC-DCI.

Hereinafter, a method for effectively transmitting eIMTA DCI will bedescribed. The eIMTA refers to a case where TDD UL-DL configuration ofeach cell is different in a state in which cells operating by TDD areaggregated. When cell(s) more than the existing case operate in theeIMTA mode in an environment in which cell(s) more than the existing 5cells are configured through CA, a method for effectively transmitting a(corresponding eIMTA cell(s)-related) eIMTA DCI is required.

For example, the (corresponding eIMTA cell(s)-related) eIMTA DCI may betransmitted through an SS of a predefined (or signaled) cell (e.g.,Pcell common search space (CSS) or through DL cell (C)SS interworkingwith a cell_PUCCH.

For example, through application of the following method, (1) a problemthat only a limited number of UL-DL configuration indicators (e.g., 3bits) are transmitted through (one) eIMTA DCI and/or (2) a problem ofcongestion of an SS (e.g., Pcell CSS or DL cell (C)SS interworking withthe cell_PUCCH) of a predefined (or signaled) specific cell in which theeIMTA DCI is transmitted, and the like, may be alleviated.

Also, for example, the [proposed method #19] is limitedly applied onlyto a case where a massive CA mode in which more than 5 cells areaggregated is configured, a case where (eIMTA) cell(s) (or (eIMTA)Lcell(s), (eIMTA) Ucell(s), or (eIMTA) Lcell(s)/Ucell(s)) are configuredto be equal to or greater than a predefined (or signaled) number (or acase where configured (eIMTA) cell(s) (configured (eIMTA) Lcell(s),configured (eIMTA) Ucell(s), or configured (eIMTA) Lcell(s)/Ucell(s))are configured to be equal to or greater than a predefined (or signaled)number), and/or a case where activated (eIMTA) cell(s) (activated(eIMTA) Lcell(s), activated (eIMTA) Ucell(s), or activated (eIMTA)Lcell(s)/Ucell(s)) are configured to be equal to or greater than apredefined (or signaled) number.

Here, for example, a rule may be defined such that the existing (REL-12LTE) operation is applied to a case where the massive CA mode is notconfigured, a case where (eIMTA) cell(s) ((eIMTA) Lcell(s), (eIMTA)Ucell(s), or (eIMTA) Lcell(s)/Ucell(s)) are configured to be smallerthan a predefined (or signaled) number, a case where configured (eIMTA)cell(s) (configured (eIMTA) Lcell(s), configured (eIMTA) Ucell(s) (orconfigured (eIMTA) Lcell(s)/Ucell(s)) are configured to be smaller thana predefined (or signaled) number), and/or a case where activated(eIMTA) cell(s) (activated (eIMTA) Lcell(s), activated (eIMTA) Ucell(s),or activated (eIMTA) Lcell(s)/Ucell(s)) are configured to be smallerthan the predefined (or signaled) number.

[Proposed method #19] A rule may be defined (hereinafter, referred to as“OPTION#A”) such that pieces of subframe position information in whichrelated eIMTA DCI is received by eIMTA cell (groups) are (partially orentirely) different, and/or a rule may be defined such that pieces of(eIMTA-)RNTI (hereinafter, referred to as “OPTION#B”) information (usedfor receiving/decoding eIMTA DCI) are (partially or entirely) different.Also, a rule may be defined such that pieces of field positioninformation on eIMTA DCI in which updated UL-DL configuration (of eIMTAcell (group)) is received are (partially or entirely) different, a rulemay be defined such that pieces of reconfiguration periodicityinformation are (partially or entirely) different, and/or a rule may bedefined such that cells and/or SS types in which eIMTA DCI is receivedare (partially or entirely) different.

Here, in an example of a case in which such a rule is applied, differenteIMTA DCI reception subframe position information and different(eIMTA-)RNTI information (used for receiving/decoding eIMTA DCI) areconfigured by eIMTA cell (groups), or a common eIMTA DCI receptionsubframe position information (between eIMTA cell (groups) and(eIMTA-)RNTI information (used for receiving/decoding eIMTA DCI)different for each eIMTA cell (group) may be configured, or common eIMTARNTI information (used for receiving/decoding eIMTA DCI) (between eIMTAcell (groups)) and eIMTA DCI reception subframe position informationdifferent in eIMTA cell (groups) may be configured.

Also, in another example, a network (or a BS) may inform(configurability) the UE about one applied rule among the OPTION#A ruleand the OPTION#B rule through predefined signaling (e.g., higher layersignaling or physical layer signaling) in consideration of factors suchas (1) how many UL-DL configuration indicators (e.g., 3 bits) can be(simultaneously) transmitted through (one) eIMTA DCI (under the currentsystem bandwidth) and/or (2) to which degree an SS (e.g., Pcell SS or DLcell (C)SS) interworking with a cell_PUCCH) of a predefined (orsignaled) specific cell in which the eIMTA DCI is transmitted iscongested, and the like.

Hereinafter, methods for effectively configuring(/signaling) (a maximumnumber) of blind decoding (BD) per cell based on (some or all of) theforegoing proposed methods will be described.

[Proposed method #25] When TDD cells for which different TDD UL-DLconfiguration(s) are configured are configured by CA (or when TDDcell(s) and FDD cell(s) are configured by CA), the number of DL subframe(SF) cells may differ by subframes. Thus, in consideration of this, thenumber of BD related to a specific cell may be independently (or(partially or entirely) differently) set by subframes. When this methodis applied, the number of BD related to the UL SF cell(s) may be(re)allocated to DL SF cell(s) at a specific timing.

[Proposed method #26] (In the case of a specific cell (e.g., Scell), thenumber of (USS) BD may be independently (or (partially or entirely)differently) set by DCI formats. For example, the number of (USS) BD maybe independently set for each of a DCI format 2D(/4), a TM-dependent DCIformat, and a DCI format 1A(/0), a fallback DCI format. For example,extremely, the number of (USS) BD regarding a specific DCI format (e.g.,DCI format 1A/0) related to a specific cell (e.g., Scell) may be set to0, so that (USS0 monitoring (or BD) may not be performed on the specificDCI format (e.g., the DCI format 1A/0) related to the specific cell(e.g., Scell).

Here, for example, when such a method is applied, a transmissionopportunity may be increased or a blocking probability may be lowered byallocating a relatively large number of BD to a DCI format having arelatively large payload size. This results from consideration of a highpossibility that a relatively high aggregation level (AL) is used fortransmission of a DCI format having a large payload size to ensurereliable transmission.

Also, in another example, since a negative influence (e.g., causinglarge size PUCCH format TX (transmission)) of DL DCI (format) falsedetection on a system is relatively large, compared with a case of ULDCI (format) false detection, the number of BD for the DL DCI format andUL DCI format in the case of a specific cell may be independently (or(partially or entirely) differently) set.

[Proposed method #27] The BS may inform about “the number/position of(E)PDCCH candidates of a specific AL” on which BD is actually performed,in a “full bitmap” form.

For example, regarding a USS of a specific cell, it is assumed that thenumber of BD for AL 1 is 6, the number of BD for AL 2 is 6, the numberof BD for AL 4 is 2, and the number of BD for AL 8 is 2. Also, it isassumed that the numbers of (E)PDCCH candidates regarding ALs 1, 2, 4, 8are sequentially 6, 6, 2, 2. Here, the BS may inform about “thenumber/position of (E)PDCCH candidates of the specific AL” on which BDis actually performed by a 16-bit bitmap.

For example, when a bitmap of ‘101000 010100 10 01’ is signaled, the UEmay actually perform BD on first and third (E)PDCCH candidates, among atotal of six (E)PDCCH candidates regarding the AL 1, on second andfourth (E)PDCCH candidates among the total of six (E)PDCCH candidatesregarding AL 2, on a first (E)PDCCH candidate among the total of two(E)PDCCH candidates regarding AL 4, and on second (E)PDCCH candidateamong the total of two (E)PDCCH candidates regarding AL 8.

[Proposed method #28] Information related to) “the number of (E)PDCCHcandidates of a specific AL on which BD is (actually) performed percell.

For example, such a proposed method may be limitedly used for thepurpose of providing (information related to) the number of (E)PDCCHcandidates related to a specific AL on an (E)PDCCH per cell. Forexample, it is assumed that, in a USS of a specific cell, the number ofBD for AL 1 is 6, the number of BD for AL 2 is 6, the number of BD forAL 4 is 2, and the number of BD for AL 8 is 2. Here, the BS may provide(information related to) “the number of (E)PDCCH candidates of aspecific AL (related to a specific cell) through a 10-bit bitmap. Forexample, in the 10-bit bitmap, first three bits may represent the numberof BD on AL 1, next three bits may represent the number of BD on AL 2,the next two bits may represent the number of BD on AL 4, and theremaining two bits may represent the number of BD on AL 8.

Informing using the bit map is merely illustrative. That is, the BS mayinform about the number of (USS) PDCCH candidates or the number of (USS)EPDCCH candidates of each AL of each cell through higher layer signalingsuch as RRC signaling. Here, the BS may explicitly inform about thenumber of (USS) PDCCH candidates or the number of (USS) EPDCCHcandidates of each AL of each cell or may inform about how many existing(USS) PDCCH candidates or (USS) EPDCCH candidates of each AL of eachcell are to be reduced (that is, the number of finally applied (E)PDCCHcandidates (of each AL) may be derived through calculation of areduction rate value (of each AL of each cell) (e.g., “ROUND (reductionrate value*number of existing (USS) (E)PDCCH candidates)”.

For example, it is assumed that eight cells (cell #1 to #8) areaggregated to the UE and cross-carrier scheduling is configured so thatscheduling information regarding eight cells is transmitted through onecell (cell #1). Here, the number of (USS) BD to be performed on each ALby cells in the USS of the cell #1 may be determined. For example, it isassumed that the number of (USS) BD called N_(K) is determined on AL #Krelated to a specific cell #X. N_(K) may be considered to indicate thenumber of existing (USS) PDCCH candidates or the number of (USS) EPDCCHcandidates.

Here, however, it may be required to reduce the number of partial (USS)BD related to some cells due to a limitation in the number of (USS) BDwhich can be maximally supported (or performed) (for each subframe)(reported by UE capability) by the UE. In this case, for example, whenthe [proposed method #28] is applied, it is possible to configure(information related to) the number of (E)PDCCH candidates of eachspecific AL of an (E)PDCCH USS of optimal (cells) in consideration of atransmission mode of each cell (which affects a payload size of a DCI,for example) and/or a (control) channel state, and the like.

In this case, the BS may provide, to the UE, information indicating howmany N_(K), the number of (USS) BD regarding AL #K related to the cell#X (i.e., the number of (USS) (E)PDCCH candidates), is to be reduced.For example, the information may consist of 2 bits and informs such that“00” indicates 0% of N_(K) (that is, it indicates absence of (USS)(E)PDCCH candidate for AL #K), “01” indicates 33% of N_(K), “10”indicates 66% of N_(K), and “11” indicates 100% of N_(K) (that is, it isthe same as N_(K)). Here, it may be convenient to indicate the finallyderived number of (USS) BD (or the number of (USS) (E)PDCCH candidates)as an integer, and thus, the finally derived number of (USS) BD may bedetermined as a result value obtained by applying a function such asROUND(/FLOOR/CEIL), and the like, to the value “reduction ratevalue*number of existing (USS) (E)PDCCH candidates”. In this example,only the number of (USS) BD regarding AL #K related to the cell #X isdescribed, but the present disclosure is not limited thereto and the BSmay provide the 2-bit information regarding each AL of each cell.

FIG. 15 illustrates an example in which a UE blind-decodes only some(E)PDCCH candidates on the basis of signaled information, among theexisting (USS) (E)PDCCH candidates related to a specific cell.

Referring to FIG. 15, it is illustrated that, regarding AL #M related toa specific cell, the number of existing (USS) (E)PDCCH candidates is Kbut the number of (USS) (E)PDCCH candidates to be actually blind-decodedis derived (or signaled) as “P”. For example, the BS may reduce K, thenumber of (USS) (E)PDCCH candidates related to AL #M of a specific cell,to 33% with 2-bit information, and here, ROUND(K*0.33)=P.

In this case, the UE (actually) performs BD from a first (USS) (E)PDCCHcandidate to Pth (USS) (E)PDCCH candidate (sequentially (or in (USS)(E)PDCCH candidates index) ascending order)), among a total of K numberof (USS) (E)PDCCH candidates related to AL #M of the specific cell.

Here, in another example, the BS may transfer, to the UE, predefined(additional) signaling (e.g., higher layer signaling or physical layersignaling) (referred to as “ORDER_INDI”) to thereby inform about inwhich manner (/direction) the signaled “P” number of (USS) (E)PDCCHcandidates (related to the corresponding specific AL), among the total“K” number of (USS) (E)PDCCH candidates related to the specific AL, isselected.

In a specific example, through ORDER_INDI (e.g., 1 bit), whether thesignaled “P” number of (USS) (E)PDCCH candidates (related to thecorresponding specific AL), among the total “K” number of (USS) (E)PDCCHcandidates related to the specific AL, is selected in ascending order of(USS) (E)PDCCH candidate index (for example, the UE (actually) performsBD from a first (USS) (E)PDCCH candidate to Pth (USS) (E)PDCCH candidate(sequentially (or in (USS) (E)PDCCH candidates index ascending order),or in descending order (for example, the UE (actually) performs BD fromthe Kth (USS) (E)PDCCH candidate to (K−P+1)th (USS) (E)PDCCH candidatein reverse order (or in (USS) (E)PDCCH candidates index descendingorder).

Also, in another example, when information regarding the number of (USS)(E)PDCCH candidate(s) related to ‘AL 4’ and/or ‘AL 8’ (on which BD is tobe (actually) performed) is provided, ‘(full) bitmap’ form (based on the[proposed method #27]) may be exceptionally used. Through this, thenumber/position of (USS)(E)PDCCH candidates of ‘AL 4’ and/or ‘AL 8’ (onwhich BD is to be (actually) performed), without a change in a size of(related) bitmap (e.g., 2 bits), may be informed in detail (orspecifically).

FIG. 16 illustrates an example of applying the aforementioned proposedmethod #28.

Referring to FIG. 16, the UE reports UE capability information to the BS(S710). As described above, the UE capability information may include‘BD CAPABILITY INFOMRATION’ indicating (USS) DL control channel decodingcapability (or a (maximum) number) of each subframe. That is, the UEreports capability (or (maximum) number) for decoding (USS) DL controlchannel by subframes to a network. For example, the UE may report a(maximum) number for blind-decoding a PDCCH and/or an EPDCCH in aUE-specific search space (USS) by subframes to the network. Here, forexample, the UE may support aggregation of more than 5 cell (carriers).

The BS determines the number of PDCCH (and/or EPDCCH) candidatesregarding each AL of the USS of each cell on the basis of thecorresponding UE capability information (S720).

The BS provides control channel candidate number information to the UE(S730).

The control channel candidate number information may be provided to theUE through a higher layer signal such as an RRC message. As describedabove, the control channel candidate number information indicates thenumber of control channel candidates regarding each aggregation level(AL) of a search space (SS) per cell.

For example, the control channel candidate number information isinformation indicating the number of PDCCH candidates and/or EPDCCHcandidates regarding each AL in a UE-specific search space (USS) of eachcell (which the UE is to (actually) perform) and 2-bit informationindicating how many existing (E)PDCCH candidates are to be reduced maybe provided by ALs (of the USS per cell). That is, the control channelcandidate number information indicates a ratio of the number of firstsome control channel candidates to be actually monitored by the UE tothe number of existing control channel candidates of each AL of the(UE-specific) SS per cell. In cases where the 2 bits are ‘00’, ‘01’,‘10’, and ‘11’, the ratios are sequentially 0, 0.33, 0.66, and 1. Thishas been described in detail above.

In this example, it is assumed that, when the number of existing (USS)(E)PDCCH candidates regarding an AL #M of a specific cell is K, (USS)(E)PDCCH candidate number information related to corresponding cell (onthe basis of the methods described above) is derived (or signaled) as P(K>P).

The BS transmits scheduling information to the UE (S740). Here, the BSmay transmit scheduling information regarding each cell to the UE on thebasis of the control channel candidate number information (S730)provided to the UE from the BS.

In order to detect a specific cell-related DCI, the UE monitors first Pnumber of (E)PDCCH candidates among existing (E)PDCCH candidates (Knumber of candidates) related to the AL #M on the basis of thecorresponding cell-related control channel candidate number information(S730) (S750).

[Proposed method #29] A total number of (E)PDCCH candidates on which BDis (actually) performed (without differentiation of ALs per cell may beinformed.

Here, in a specific example, it is assumed that, regarding a USS of aspecific cell, the number of BD for AL 1 is 6, the number of BD for AL 2is 6, the number of BD for AL 4 is 2, and the number of BD for AL 8 is2. In this case, a total number of (E)PDCCH candidates on which BD is(actually) performed may be informed by 4 bits (bitmap). For example, incases where a total number of (E)PDCCH candidates on which BD is(actually) performed is signaled as 10, 10 (E)PDCCH candidates may beselected and (actually) blind-decoded, sequentially (or in (AL indexand/or (E)PDCCH candidate index) ascending order) starting from a first(E)PDCCH candidate, among (the entire) 16 USS (E)PDCCH candidate(s).

[Proposed method #30] A supportable maximum number of BD reported by theUE will be termed “MAX_BDCAPA_NUM”, and a (maximum) number of BD relatedto false detection (occurrence) probability less than a predefined (orsignaled) threshold value will be termed “MAX_FALBD_NUM”. For example,in a situation in which N number of cells are configured by CA, when atotal number of BD calculated according to the existing BD method/rule(that is, ‘N*K’, here, ‘K’ is the number of BD per cell according to theexisting method (e.g., ‘32 BD(s) per (S)cell’)) is termed“TOTAL_BD_NUM”, (some or all of) the following rules may be applied.

(Rule #30-1) BD may be performed on CA (i.e., N) satisfying both‘MAX_BDCAPA_NUM>TOTAL_BD_NUM’ and ‘MAX_FALBD_NUM>TOTAL_BD_NUM’ accordingto “TOTAL_BD_NUM” based on the existing method, without separately(re)setting(/signaling) “the number of BD per cell”.

(Rule #30-2) BD may be performed on CA (i.e., N) in which‘MAX_BDCAPA_NUM<TOTAL_BD_NUM’ or ‘MAX_FALBD_NUM<TOTAL_BD_NUM’ accordingto (re)setting newly signaled (/defined) “number of BD per cell”.

[Proposed method #31] For example, in order to signal (/set) a BD value(or (E)PDCCH candidate number) regarding different control channelstructure/control channel sets (e.g., the same and/or different ALs(termed “AL type”) of PDCCH and EPDCCH (set #1/#2), a limited “N” numberof bits (e.g., 2 bits) which are previously set (/signaled) by AL typesmay be used (OPTION #31-A) That is, in order to allocate a BD value (orthe number of (E)PDCCH candidates) of each AL type, “N” number of bits(e.g., 2 bits) may be used.

Table 22 below illustrates a total (maximum) of BD value candidates (or(E)PDCCH candidate number candidates) of each control channelstructure/control channel set of each of predefined (or signaled) ALtypes.

TABLE 22 Total (maximum) Total (maximum) Total (maximum) Total (maximum)Total (maximum) BD value BD value BD value BD value BD value candidatescandidates candidates candidates candidates related to related torelated to related to related to first AL type second AL type third ALtype fourth AL type fifth AL type (or (E)PDCCH (or (E)PDCCH (or (E)PDCCH(or (E)PDCCH (or (E)PDCCH candidate candidate candidate candidatecandidate Control type number candidates) number candidates) numbercandidates) number candidates) number candidates) PDCCH 6 6 2 2 one 4,6, 8 2, 4, 5, 6 1, 2, 3 1, 2 1 EPDCCH set is configured Two First FirstFirst First First EPDCCH EPDCCH EPDCCH EPDCCH EPDCCH EPDCCH set(s) areSET: 2, 3, 4, 5, 6 SET: 2, 3, 4 SET: 1, 2, 3, 4 SET: 1 SET: 1 configuredSecond Second Second Second Second EPDCCH EPDCCH EPDCCH EPDCCH EPDCCHset: 1, 2, 3, 4 set: 1, 2, 3, set: 1, 2, 4 set: 1, 2 set: 1

Here, for example, in the case of PDCCH, “first AL type, second AL type,third AL type, fourth AL type, and fifth AL type” may respectively bedefined(/interpreted) as “AL1, AL2, AL4, AL8, and N/A”, and also, in thecase of EPDCCH, “first AL type, second AL type, third AL type, fourth ALtype, and fifth AL type” may respectively be defined(/interpreted) as“AL1, AL2, AL4, AL8, and AL16” (and/or “AL2, AL4, AL8, AL16, AND AL32”).When (OPTION #31-A) described above is applied, for example, if a total(maximum) number of PDCCH/EPDCCH candidates (or BD value) related todifferent control channel structure/control channel sets (e.g., PDCCHand EPDCCH (set #1/#2)) configured to the UE is “N” or smaller regardingall the AL(s) within the (specific) AL type, “N” number of bits (withinthe corresponding (specific) AL type) may be interpreted according tothe [proposed method #27] (that is, the method of indicating the“number/position of PDCCH/EPDCCH candidates of specific AL” on which BDis (actually) performed per cell, in the form of “full bitmap”).

Here, for example, such a rule may be applied to a case where “N” isdefined(/signaled) as ‘2’ and a total (maximum) BD value (or the numberof (E)PDCCH candidates) related to a third AL type of a PDCCH and onepreviously configured (/signaled) EPDCCH set are respectively set to‘2’, ‘2’ (and/or ‘1’) (or a case where a total (maximum) BD value (orthe number of (E)PDCCH candidates) related to a third AL type of a PDCCHand first/second previously configured (/signaled) EPDCCH set arerespectively set to ‘2’, ‘2/2’ (and/or ‘1/2’ and/or ‘2/1’, and/or ‘1/1’)

In such a case, for example, the corresponding 2 bits directly indicatethe number/position of PDCCH/EPDCCH candidates related to a third ALtype on which BD is (actually) performed (e.g., ‘00’, ‘01’, ‘10’, and‘11’ respectively directly indicate that ‘the number (/position) ofPDCCH/EPDCCH candidates on which BD is (actually) performed is notpresent’, ‘the number (/position) of PDCCH/EPDCCH candidates on which BDis (actually) performed is one/first PDCCH/EPDCCH candidate’, ‘number(/position) of PDCCH/EPDCCH candidates on which BD is (actually)performed is one/second PDCCH/EPDCCH candidate’, and ‘number (/position)of PDCCH/EPDCCH candidates on which BD is (actually) performed istwo/first and second PDCCH/EPDCCH candidates’).

Meanwhile, for example, if a total (maximum) number of PDCCH/EPDCCHcandidates (or BD value) (which are termed (“PDCCH_MAXBDNUM” and“EPDCCH_MAXBDNUM”) related to different control channelstructure/control channel sets (e.g., PDCCH and EPDCCH (set #1/#2))configured to the UE exceeds “N” regarding at least one AL (or all theAL(s) within the (specific) AL type, “N” number of bits (within thecorresponding (specific) AL type) may be used for the purpose ofindicating a predefined(/signaled) percent value (e.g., it may beconfigured such that ‘00’, 01’, ‘10’, and ‘11’ indicate ‘0%’, ‘33%’,‘66%’, and ‘100%’, respectively). Here, for example, such a rule may beapplied to a case where “N” is defined(/signaled) as ‘2’ and a total(maximum) BD value (or the number of (E)PDCCH candidates) related to asecond AL type of a PDCCH and one previously configured (/signaled)EPDCCH set are respectively set to ‘6’, ‘4’.

In this case, for example, if the corresponding 2 bits aresignaled(/set) to ‘01’, the number(/position) of PDCCH/EPDCCH candidateson which BD is actually performed are ‘ROUND(6*0.33)’ (or‘FLOOR(6*0.33)’ or ‘CEILING(6*0.33)’), ‘ROUND(4*0.33)’ (or‘FLOOR(4*0.33)’ or ‘CEILING(4*0.33)’), respectively, (in ascending order(or descending or) of PDCCH/EPDCCH candidate index)

Also, in another example, when (OPTION #31-A) described above isapplied, for example, if a total (maximum) number of PDCCH/EPDCCHcandidates (or BD value) related to different control channelstructure/control channel sets (e.g., PDCCH and EPDCCH (set #1/#2))configured to the UE is “N” or smaller regarding some of the AL(s)within the (specific) AL type, “N” number of bits may also be configuredto be interpreted according to the [proposed method #27] (that is, themethod of indicating the “number/position of PDCCH/EPDCCH candidates ofspecific AL” on which BD is (actually) performed per cell, in the formof “full bitmap”) only for some AL(s) (within the corresponding(specific) AL type) (e.g., the ‘N’ number of bits are used for thepurpose of indicating a predefined(/signaled) percent value for theother remaining AL(s) (within the corresponding (specific) AL type).

Table 23 below illustrates an example of a case in which a plurality ofpreviously configured(/signaled) AL type(s) in Table 22 are(re)defined(/(re)integrated) (or bound) to one (representative) AL type.

TABLE 23 Total (maximum) Total (maximum) Total (maximum) Total (maximum)BD value BD value BD value BD value candidates candidates candidatescandidates related to related to related to related to first AL typesecond AL type third AL type fourth AL type (or (E)PDCCH (or (E)PDCCH(or (E)PDCCH (or (E)PDCCH candidate candidate candidate candidateControl type number candidates) number candidates) number candidates)number candidates) PDCCH 6 6 2 2 one 4, 6, 8 2, 4, 5, 6 1, 2, 3 1, 2, 3EPDCCH set is configured Two First First First First EPDCCH EPDCCHEPDCCH EPDCCH EPDCCH set(s) are SET: 2, 3, 4, 5, 6 SET: 2, 3, 4 SET: 1,2, 3, 4 SET: 1, 2 configured Second Second Second Second EPDCCH EPDCCHEPDCCH EPDCCH set: 1, 2, 3, 4 set: 1, 2, 3, set: 1, 2, 4 set: 1, 2, 3

Table 23 illustrates a case where ‘fourth AL type’ and ‘fifth AL type’in Table 23 are (re)defined(/(re)integrated) to one (representative ALtype (e.g., (representative) fourth AL type (Table 23)). Here, forexample, a total (maximum) BD value (or (E)PDCCH candidate number)related to the fifth AL type of Table 22 may be set or not. Thus, a(specific) total (maximum) BD value (or (E)PDCCH candidate number)related to the (representative) fourth AL type of Table 23 may includethe sum of the total (maximum) BD values (or (EPDCCH candidate numbers)related to partially (or entirely) different AL(s) (CASE #31-1) or mayinclude the sum of the total (maximum) BD values (or (E)PDCCH candidatenumbers) related to the same AL(s) (CASE #31-2).

Here, for example, in the case of (CASE #32-1) (and/or (CASE #32-2),when ‘N’ number of bits are used according to the [proposed method #27](that is, the method of indicating the “number/position of PDCCH/EPDCCHcandidates of specific AL” on which BD is (actually) performed per cell,in the form of “full bitmap”), and/or ‘N’ number of bits are used forthe purpose of indicating predefined(/signaled) percent value (e.g.,‘00’, 01’, ‘10’, and ‘11’ are respectively configured to indicate ‘0%’,‘33%’, ‘66%’, and ‘100%’), the final number/position of EPDCCHcandidates on which BD is (actually) performed may bedetermined(/selected) after (some or all of) the following interleavingrules are applied.

Hereinafter, for the purposes of description, it is assumed that a total(maximum) BD value (or EPDCCH candidate number) of the (representative)fourth AL type related to one ((re)defined(/(re)integrated)) EPDCCH setincludes ‘AL8-related two EPDCCH candidate(s) (e.g., AL8_EPDCCHCANDI#1and AL8_EPDCCHCANDI#2)‘ and’AL16-related one EPDCCH candidate(s) (e.g.,)AL16_EPDCCHCANDI#1)’.

(Rule #31-1) For example, a rule may be defined such that (E)PDCCHcandidate(s) of a relatively high (or low) AL are positioned ahead.

(Rule #31-2) For example, a rule may be defined such that (E)PDCCHcandidate of a relatively low (or high) (E)PDCCH candidate index ispositioned ahead. This rule may be used to (re)define a dispositionorder of the same AL-related (E)PDCCH candidate(s). In cases whereinterleaving rule(s) based on (Rule #31-1) and/or (Rule #31-2) areapplied to the assumed example situation, ‘AL16_EPDCCHCANDI#1,AL8_EPDCCHCANDI#1, and AL8_EPDCCHCANDI#2 (that is, a case where the(E)PDCCH candidate(s) of the relatively high AL and the (E)PDCCHcandidate of the relatively low (E)PDCCH candidate index are configuredto be positioned ahead)’ (or ‘AL8_EPDCCHCANDI#1, AL8_EPDCCHCANDI#2,AL16_EPDCCHCANDI#1’ (that is, a case where the (E)PDCCH candidate(s) ofthe relatively low AL and the (E)PDCCH candidate of the relatively low(E)PDCCH candidate index are configured to be positioned ahead) aremixed.

[Proposed method #32] if (in the case of applying the [proposed method#31]) two EPDCCH set(s) are configured and a predefined (/signaled)percent value indicated by ‘N’ number of bits (e.g., 2 bits) (e.g.,‘00’, 01’, ‘10’, and ‘11’ may be configured to respectively indicate‘0%’, ‘³³%’, ‘66%’, and ‘100%’) is applied to the sum of a total(maximum) BD value (or EPDCCH candidate number) related to the twoEPDCCH set(s), a final number/position of EPDCCH candidates on which BDis (actually) performed may be determined(/selected) after EPDCCHcandidate(s) are interleaved according to (some or all of) the followingrules.

Hereinafter, for the purposes of description, it is assumed that a total(maximum) BD value (or EPDCCH candidate number) of first/second EPDCCHsets is set to ‘6 (e.g., FIRSTSET_IDX#1, FIRSTSET_IDX#2, FIRSTSET_IDX#3,FIRSTSET_IDX#4, FIRSTSET_IDX#5, FIRSTSET_IDX#6) and ‘3 (e.g.,‘SECONDSET_IDX#1, SECONDSET_IDX#2, SECONDSET_IDX#3)’ and bits of ‘N=2’are signaled(/set) to ‘01’.

(Rule #32-1) It may be defined such that, between EPDDCH set-relatedEPDCCH candidates having a relatively large “total (maximum) BD value(or EPDCCH candidate number) (which is termed “LARGER_BDNUM”)’, anEPDCCH candidate(s) related to an EPDCCH set having a relatively small‘total (maximum) BD value (or the EPDCCH candidate number) (which istermed “SMALLER_BDNUM”)’ are inserted with an offset (/interval) of‘FLOOR(LARGER_BDNUM/SMALLER_BDNUM)’ (or‘FLOOR(LARGER_BDNUM/SMALLER_BDNUM)’ or‘CEILING(LARGER_BDNUM/SMALLER_BDNUM)’) (or a previouslysignaled(/configured) offset (/interval)).

Here, for example, when such an interleaving rule is applied in theassumed example situation, EPDCCH candidate(s) related to two EPDCCHset(s) are mixed in the form of ‘FIRSTSET_IDX#1, FIRSTSET_IDX#2,SECONDSET_IDX#1, FIRSTSET_IDX#3, FIRSTSET_IDX#4, SECONDSET_IDX#2,FIRSTSET_IDX#5, FIRSTSET_IDX#6, SECONDSET_IDX#3’, and a finalnumber/position of EPDCCH candidates on which BD is (actually) performedby bits of signaled(/configured) ‘01’ (i.e., ‘33%’) are‘ROUND(9*0.33)(=3)’/‘FIRSTSET_IDX#1, FIRSTSET_IDX#2, SECONDSET_IDX#1’(or ‘FLOOR(9*0.33)(=2)’/‘FIRSTSET_IDX#1, FIRSTSET_IDX#2’ or‘CEILING(9*0.33)(=3)’/‘FIRSTSET_IDX#1, FIRSTSET_IDX#2,SECONDSET_IDX#1’).

When such an interleaving rule is applied in the assumed examplesituation, EPDCCH candidate(s) related to two EPDCCH set(s) are mixed inthe form of ‘SECONDSET_IDX#1, FIRSTSET_IDX#1, FIRSTSET_IDX#2,SECONDSET_IDX#2, FIRSTSET_IDX#3, FIRSTSET_IDX#4, SECONDSET_IDX#3,FIRSTSET_IDX#5, FIRSTSET_IDX#6’, and a final number/position of EPDCCHcandidates on which BD is (actually) performed by bits ofsignaled(/configured) ‘01’ (i.e., ‘33%’) are‘ROUND(9*0.33)(=3)’/‘SECONSECONDSET_IDX#1, FIRSTSET_IDX#1,FIRSTSET_IDX#2’ (or ‘FLOOR(9*0.33)(=2)’/‘SECONDSET_IDX#1,FIRSTSET_IDX#1’ or ‘CEILING(9*0.33)(=3)’/‘SECONDSET_IDX#1,FIRSTSET_IDX#1, FIRSTSET_IDX#2’).

Embodiments regarding the aforementioned proposed methods are alsoincluded as one of implementation methods of the present disclosure, andthus, they are obviously regarded as a sort of proposed methods. Also,the aforementioned proposed methods may be independently implemented ormay also be implemented in the form of combination (or merging) of someproposed methods.

In another example, a rule may be defined such that some (or all) of theaforementioned proposed methods are limitedly applied only to asituation of cross-carrier scheduling (CCS) (and/or self-scheduling(SFS)).

Also, for example, a rule may be defined such that some (or all) of theaforementioned proposed methods are limitedly applied only to a casewhere Scell (not Pcell) PUCCH transmission mode is configured.

Also, for example, some (or all) of the aforementioned proposed methodsmay also be extendedly applied between Lcell(s) and Lcell(s) (or betweenLcell(s) and Ucell(s) or between Ucell(s) and Ucell(s)). Also, forexample, a rule may be defined such that the aforementioned proposedmethods (e.g., (maximum) BD (number) reduction method and SS sharingmethod) are limitedly applied only to a case where a massive CA mode isconfigured, a case where cell(s) (Lcell(s), Ucell(s), orLcell(s)/Ucell(s)) are configured to be equal to or greater than apredefined (or signaled) number (or a case where configured cell(s)(configured Lcell(s), configured Ucell(s), or configuredLcell(s)/Ucell(s)) are configured to be equal to or greater than apredefined (or signaled) number), a case where activated cell(s)(activated Lcell(s), activated Ucell(s), or activated Lcell(s)/Ucell(s))are configured to be equal to or greater than a predefined (or signaled)number, and/or a case where the number of scheduled cell(s) configuredin one scheduling cell is equal to or greater than a predefined (orsignaled) threshold value.

Here, for example, a rule may be defined such that the existing (REL-12LTE) operation is applied to a case where the massive CA mode is notconfigured, a case where cell(s) (Lcell(s), Ucell(s), orLcell(s)/Ucell(s)) are configured to be smaller than a predefined (orsignaled) number, a case where configured cell(s) (configured Lcell(s),configured Ucell(s) (or configured Lcell(s)/Ucell(s)) are configured tobe smaller than a predefined (or signaled) number), a case whereactivated cell(s) (activated Lcell(s), activated Ucell(s), or activatedLcell(s)/Ucell(s)) are configured to be smaller than a predefined (orsignaled) number, and/or a case where the number of scheduled cell(s)configured in one scheduling cell is smaller than a predefined (orsignaled) threshold value.

Also, for example, the term “CG” in the present disclosure may beinterpreted as generally referring to cell(s) interworking with aspecific cell (i.e., termed “cell_PUCCH”) in which PUCCH transmission isconfigured (or allowed). Here, for example, one CG may be interpreted asindicating a specific cell_PUCCH and cell(s) in which a (PUCCH-based)UCI is transmitted through the corresponding cell_PUCCH (together), orone CG may be interpreted as indicating only cell(s) in which a(PUCCH-based) UCI is transmitted through a specific cell_PUCCH (but notincluding the corresponding cell_PUCCH).

FIG. 17 is a block diagram illustrating a BS and a UE.

The BS 100 includes a processor 110, a memory 120, and a radio frequency(RF) unit 130. The processor 110 implements the proposed functions,processes and/or methods. The memory 120 is connected to the processor110 and stores various types of information for driving the processor110. The RF unit 130 is connected to the processor 110 and transmitsand/or receives a radio signal.

A UE 200 includes a processor 210, a memory 220, and an RF unit 130. Theprocessor 210 implements the proposed functions, processes and/ormethods. The memory 220 is connected to the processor 210 and storesvarious types of information for driving the processor 210. The RF unit230 is connected to the processor 210 and transmits and/or receives aradio signal.

The processors 110 and 210 includes may include an ASIC(Application-Specific Integrated Circuit), a chip set, a logicalcircuit, and/or a data processing device. The memories 120 and 220 mayinclude a ROM (Read-Only Memory), a RAM (Random Access Memory), a flashmemory, a memory card, a storage medium, and/or any other storagedevice. The RF units 130 and 230 may include a baseband circuit forprocessing a radio signal. When the embodiment is implemented bysoftware, the foregoing techniques may be implemented as modules(processes, functions, and the like) performing the foregoing functions.The modules may be stored in the memories 120 and 220 and executed bythe processors 110 and 210. The memories 120 and 220 may be providedwithin or outside the processors 110 and 120 and may be connected to theprocessors 110 and 210 through a well-known unit.

What is claimed is:
 1. A method for monitoring downlink controlinformation (DCI) by a user equipment (UE) in a wireless communicationsystem, the method comprising: receiving control channel candidatenumber information indicating the number of control channel candidatesfor each aggregation level (AL) of a search space (SS) per cell; andmonitoring some initial control channel candidates among legacy controlchannel candidates to detect DCI, wherein the number of the some initialcontrol channel candidates is determined on the basis of the controlchannel candidate number information.
 2. The method of claim 1, whereinthe SS is a UE-specific SS.
 3. The method of claim 1, wherein thecontrol channel candidates are candidates of a physical downlink controlchannel (PDCCH) or an enhanced physical downlink control channel(EPDCCH).
 4. The method of claim 1, wherein the control channelcandidate number information is provided as a ratio of the number of thesome initial control channel candidates to the number of the legacycontrol channel candidates.
 5. The method of claim 4, wherein thecontrol channel candidate number information is provided regarding thenumber of legacy control channel candidates per AL of an SS per cell. 6.The method of claim 5, wherein the control channel candidate numberinformation consists of 2 bits.
 7. The method of claim 6, wherein whenthe 2 bits is ‘00’, ‘01’, ‘10’, or ‘11’, ratios thereof are 0, 0.33,0.66, and 1, respectively.
 8. The method of claim 1, wherein the controlchannel candidate number information is received through a higher layersignal.
 9. The method of claim 8, wherein the higher layer signal is aradio resource control (RRC) message.
 10. The method of claim 1, whereinthe UE supports aggregation of more than 5 cells.
 11. The method ofclaim 1, wherein when the UE fails to receive the control channelcandidate number information, the UE monitors legacy control channelcandidates regarding each AL of the SS to detect DCI.
 12. A userequipment (UE), comprising: a radio frequency (RF) unit transmitting andreceiving a radio signal; and a processor connected to the RF unit,wherein the processor receives control channel candidate numberinformation indicating the number of control channel candidates for eachaggregation level (AL) of a search space (SS) per cell; and monitorssome initial control channel candidates among legacy control channelcandidates to detect DCI, wherein the number of the some initial controlchannel candidates is determined on the basis of the control channelcandidate number information.